diff --git a/vendor/gopkg.in/yaml.v3/encode.go b/vendor/gopkg.in/yaml.v3/encode.go
new file mode 100644
index 0000000..1f37271
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/encode.go
@@ -0,0 +1,561 @@
+//
+// Copyright (c) 2011-2019 Canonical Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package yaml
+
+import (
+	"encoding"
+	"fmt"
+	"io"
+	"reflect"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+	"unicode/utf8"
+)
+
+type encoder struct {
+	emitter  yaml_emitter_t
+	event    yaml_event_t
+	out      []byte
+	flow     bool
+	indent   int
+	doneInit bool
+}
+
+func newEncoder() *encoder {
+	e := &encoder{}
+	yaml_emitter_initialize(&e.emitter)
+	yaml_emitter_set_output_string(&e.emitter, &e.out)
+	yaml_emitter_set_unicode(&e.emitter, true)
+	return e
+}
+
+func newEncoderWithWriter(w io.Writer) *encoder {
+	e := &encoder{}
+	yaml_emitter_initialize(&e.emitter)
+	yaml_emitter_set_output_writer(&e.emitter, w)
+	yaml_emitter_set_unicode(&e.emitter, true)
+	return e
+}
+
+func (e *encoder) init() {
+	if e.doneInit {
+		return
+	}
+	if e.indent == 0 {
+		e.indent = 4
+	}
+	e.emitter.best_indent = e.indent
+	yaml_stream_start_event_initialize(&e.event, yaml_UTF8_ENCODING)
+	e.emit()
+	e.doneInit = true
+}
+
+func (e *encoder) finish() {
+	e.emitter.open_ended = false
+	yaml_stream_end_event_initialize(&e.event)
+	e.emit()
+}
+
+func (e *encoder) destroy() {
+	yaml_emitter_delete(&e.emitter)
+}
+
+func (e *encoder) emit() {
+	// This will internally delete the e.event value.
+	e.must(yaml_emitter_emit(&e.emitter, &e.event))
+}
+
+func (e *encoder) must(ok bool) {
+	if !ok {
+		msg := e.emitter.problem
+		if msg == "" {
+			msg = "unknown problem generating YAML content"
+		}
+		failf("%s", msg)
+	}
+}
+
+func (e *encoder) marshalDoc(tag string, in reflect.Value) {
+	e.init()
+	var node *Node
+	if in.IsValid() {
+		node, _ = in.Interface().(*Node)
+	}
+	if node != nil && node.Kind == DocumentNode {
+		e.nodev(in)
+	} else {
+		yaml_document_start_event_initialize(&e.event, nil, nil, true)
+		e.emit()
+		e.marshal(tag, in)
+		yaml_document_end_event_initialize(&e.event, true)
+		e.emit()
+	}
+}
+
+func (e *encoder) marshal(tag string, in reflect.Value) {
+	tag = shortTag(tag)
+	if !in.IsValid() || in.Kind() == reflect.Ptr && in.IsNil() {
+		e.nilv()
+		return
+	}
+	iface := in.Interface()
+	switch value := iface.(type) {
+	case *Node:
+		e.nodev(in)
+		return
+	case time.Time:
+		e.timev(tag, in)
+		return
+	case *time.Time:
+		e.timev(tag, in.Elem())
+		return
+	case time.Duration:
+		e.stringv(tag, reflect.ValueOf(value.String()))
+		return
+	case Marshaler:
+		v, err := value.MarshalYAML()
+		if err != nil {
+			fail(err)
+		}
+		if v == nil {
+			e.nilv()
+			return
+		}
+		e.marshal(tag, reflect.ValueOf(v))
+		return
+	case encoding.TextMarshaler:
+		text, err := value.MarshalText()
+		if err != nil {
+			fail(err)
+		}
+		in = reflect.ValueOf(string(text))
+	case nil:
+		e.nilv()
+		return
+	}
+	switch in.Kind() {
+	case reflect.Interface:
+		e.marshal(tag, in.Elem())
+	case reflect.Map:
+		e.mapv(tag, in)
+	case reflect.Ptr:
+		e.marshal(tag, in.Elem())
+	case reflect.Struct:
+		e.structv(tag, in)
+	case reflect.Slice, reflect.Array:
+		e.slicev(tag, in)
+	case reflect.String:
+		e.stringv(tag, in)
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		e.intv(tag, in)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		e.uintv(tag, in)
+	case reflect.Float32, reflect.Float64:
+		e.floatv(tag, in)
+	case reflect.Bool:
+		e.boolv(tag, in)
+	default:
+		panic("cannot marshal type: " + in.Type().String())
+	}
+}
+
+func (e *encoder) mapv(tag string, in reflect.Value) {
+	e.mappingv(tag, func() {
+		keys := keyList(in.MapKeys())
+		sort.Sort(keys)
+		for _, k := range keys {
+			e.marshal("", k)
+			e.marshal("", in.MapIndex(k))
+		}
+	})
+}
+
+func (e *encoder) fieldByIndex(v reflect.Value, index []int) (field reflect.Value) {
+	for _, num := range index {
+		for {
+			if v.Kind() == reflect.Ptr {
+				if v.IsNil() {
+					return reflect.Value{}
+				}
+				v = v.Elem()
+				continue
+			}
+			break
+		}
+		v = v.Field(num)
+	}
+	return v
+}
+
+func (e *encoder) structv(tag string, in reflect.Value) {
+	sinfo, err := getStructInfo(in.Type())
+	if err != nil {
+		panic(err)
+	}
+	e.mappingv(tag, func() {
+		for _, info := range sinfo.FieldsList {
+			var value reflect.Value
+			if info.Inline == nil {
+				value = in.Field(info.Num)
+			} else {
+				value = e.fieldByIndex(in, info.Inline)
+				if !value.IsValid() {
+					continue
+				}
+			}
+			if info.OmitEmpty && isZero(value) {
+				continue
+			}
+			e.marshal("", reflect.ValueOf(info.Key))
+			e.flow = info.Flow
+			e.marshal("", value)
+		}
+		if sinfo.InlineMap >= 0 {
+			m := in.Field(sinfo.InlineMap)
+			if m.Len() > 0 {
+				e.flow = false
+				keys := keyList(m.MapKeys())
+				sort.Sort(keys)
+				for _, k := range keys {
+					if _, found := sinfo.FieldsMap[k.String()]; found {
+						panic(fmt.Sprintf("cannot have key %q in inlined map: conflicts with struct field", k.String()))
+					}
+					e.marshal("", k)
+					e.flow = false
+					e.marshal("", m.MapIndex(k))
+				}
+			}
+		}
+	})
+}
+
+func (e *encoder) mappingv(tag string, f func()) {
+	implicit := tag == ""
+	style := yaml_BLOCK_MAPPING_STYLE
+	if e.flow {
+		e.flow = false
+		style = yaml_FLOW_MAPPING_STYLE
+	}
+	yaml_mapping_start_event_initialize(&e.event, nil, []byte(tag), implicit, style)
+	e.emit()
+	f()
+	yaml_mapping_end_event_initialize(&e.event)
+	e.emit()
+}
+
+func (e *encoder) slicev(tag string, in reflect.Value) {
+	implicit := tag == ""
+	style := yaml_BLOCK_SEQUENCE_STYLE
+	if e.flow {
+		e.flow = false
+		style = yaml_FLOW_SEQUENCE_STYLE
+	}
+	e.must(yaml_sequence_start_event_initialize(&e.event, nil, []byte(tag), implicit, style))
+	e.emit()
+	n := in.Len()
+	for i := 0; i < n; i++ {
+		e.marshal("", in.Index(i))
+	}
+	e.must(yaml_sequence_end_event_initialize(&e.event))
+	e.emit()
+}
+
+// isBase60 returns whether s is in base 60 notation as defined in YAML 1.1.
+//
+// The base 60 float notation in YAML 1.1 is a terrible idea and is unsupported
+// in YAML 1.2 and by this package, but these should be marshalled quoted for
+// the time being for compatibility with other parsers.
+func isBase60Float(s string) (result bool) {
+	// Fast path.
+	if s == "" {
+		return false
+	}
+	c := s[0]
+	if !(c == '+' || c == '-' || c >= '0' && c <= '9') || strings.IndexByte(s, ':') < 0 {
+		return false
+	}
+	// Do the full match.
+	return base60float.MatchString(s)
+}
+
+// From http://yaml.org/type/float.html, except the regular expression there
+// is bogus. In practice parsers do not enforce the "\.[0-9_]*" suffix.
+var base60float = regexp.MustCompile(`^[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+(?:\.[0-9_]*)?$`)
+
+// isOldBool returns whether s is bool notation as defined in YAML 1.1.
+//
+// We continue to force strings that YAML 1.1 would interpret as booleans to be
+// rendered as quotes strings so that the marshalled output valid for YAML 1.1
+// parsing.
+func isOldBool(s string) (result bool) {
+	switch s {
+	case "y", "Y", "yes", "Yes", "YES", "on", "On", "ON",
+		"n", "N", "no", "No", "NO", "off", "Off", "OFF":
+		return true
+	default:
+		return false
+	}
+}
+
+func (e *encoder) stringv(tag string, in reflect.Value) {
+	var style yaml_scalar_style_t
+	s := in.String()
+	canUsePlain := true
+	switch {
+	case !utf8.ValidString(s):
+		if tag == binaryTag {
+			failf("explicitly tagged !!binary data must be base64-encoded")
+		}
+		if tag != "" {
+			failf("cannot marshal invalid UTF-8 data as %s", shortTag(tag))
+		}
+		// It can't be encoded directly as YAML so use a binary tag
+		// and encode it as base64.
+		tag = binaryTag
+		s = encodeBase64(s)
+	case tag == "":
+		// Check to see if it would resolve to a specific
+		// tag when encoded unquoted. If it doesn't,
+		// there's no need to quote it.
+		rtag, _ := resolve("", s)
+		canUsePlain = rtag == strTag && !(isBase60Float(s) || isOldBool(s))
+	}
+	// Note: it's possible for user code to emit invalid YAML
+	// if they explicitly specify a tag and a string containing
+	// text that's incompatible with that tag.
+	switch {
+	case strings.Contains(s, "\n"):
+		if e.flow {
+			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+		} else {
+			style = yaml_LITERAL_SCALAR_STYLE
+		}
+	case canUsePlain:
+		style = yaml_PLAIN_SCALAR_STYLE
+	default:
+		style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+	}
+	e.emitScalar(s, "", tag, style, nil, nil, nil, nil)
+}
+
+func (e *encoder) boolv(tag string, in reflect.Value) {
+	var s string
+	if in.Bool() {
+		s = "true"
+	} else {
+		s = "false"
+	}
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) intv(tag string, in reflect.Value) {
+	s := strconv.FormatInt(in.Int(), 10)
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) uintv(tag string, in reflect.Value) {
+	s := strconv.FormatUint(in.Uint(), 10)
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) timev(tag string, in reflect.Value) {
+	t := in.Interface().(time.Time)
+	s := t.Format(time.RFC3339Nano)
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) floatv(tag string, in reflect.Value) {
+	// Issue #352: When formatting, use the precision of the underlying value
+	precision := 64
+	if in.Kind() == reflect.Float32 {
+		precision = 32
+	}
+
+	s := strconv.FormatFloat(in.Float(), 'g', -1, precision)
+	switch s {
+	case "+Inf":
+		s = ".inf"
+	case "-Inf":
+		s = "-.inf"
+	case "NaN":
+		s = ".nan"
+	}
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) nilv() {
+	e.emitScalar("null", "", "", yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) emitScalar(value, anchor, tag string, style yaml_scalar_style_t, head, line, foot, tail []byte) {
+	// TODO Kill this function. Replace all initialize calls by their underlining Go literals.
+	implicit := tag == ""
+	if !implicit {
+		tag = longTag(tag)
+	}
+	e.must(yaml_scalar_event_initialize(&e.event, []byte(anchor), []byte(tag), []byte(value), implicit, implicit, style))
+	e.event.head_comment = head
+	e.event.line_comment = line
+	e.event.foot_comment = foot
+	e.event.tail_comment = tail
+	e.emit()
+}
+
+func (e *encoder) nodev(in reflect.Value) {
+	e.node(in.Interface().(*Node), "")
+}
+
+func (e *encoder) node(node *Node, tail string) {
+	// If the tag was not explicitly requested, and dropping it won't change the
+	// implicit tag of the value, don't include it in the presentation.
+	var tag = node.Tag
+	var stag = shortTag(tag)
+	var rtag string
+	var forceQuoting bool
+	if tag != "" && node.Style&TaggedStyle == 0 {
+		if node.Kind == ScalarNode {
+			if stag == strTag && node.Style&(SingleQuotedStyle|DoubleQuotedStyle|LiteralStyle|FoldedStyle) != 0 {
+				tag = ""
+			} else {
+				rtag, _ = resolve("", node.Value)
+				if rtag == stag {
+					tag = ""
+				} else if stag == strTag {
+					tag = ""
+					forceQuoting = true
+				}
+			}
+		} else {
+			switch node.Kind {
+			case MappingNode:
+				rtag = mapTag
+			case SequenceNode:
+				rtag = seqTag
+			}
+			if rtag == stag {
+				tag = ""
+			}
+		}
+	}
+
+	switch node.Kind {
+	case DocumentNode:
+		yaml_document_start_event_initialize(&e.event, nil, nil, true)
+		e.event.head_comment = []byte(node.HeadComment)
+		e.emit()
+		for _, node := range node.Content {
+			e.node(node, "")
+		}
+		yaml_document_end_event_initialize(&e.event, true)
+		e.event.foot_comment = []byte(node.FootComment)
+		e.emit()
+
+	case SequenceNode:
+		style := yaml_BLOCK_SEQUENCE_STYLE
+		if node.Style&FlowStyle != 0 {
+			style = yaml_FLOW_SEQUENCE_STYLE
+		}
+		e.must(yaml_sequence_start_event_initialize(&e.event, []byte(node.Anchor), []byte(tag), tag == "", style))
+		e.event.head_comment = []byte(node.HeadComment)
+		e.emit()
+		for _, node := range node.Content {
+			e.node(node, "")
+		}
+		e.must(yaml_sequence_end_event_initialize(&e.event))
+		e.event.line_comment = []byte(node.LineComment)
+		e.event.foot_comment = []byte(node.FootComment)
+		e.emit()
+
+	case MappingNode:
+		style := yaml_BLOCK_MAPPING_STYLE
+		if node.Style&FlowStyle != 0 {
+			style = yaml_FLOW_MAPPING_STYLE
+		}
+		yaml_mapping_start_event_initialize(&e.event, []byte(node.Anchor), []byte(tag), tag == "", style)
+		e.event.tail_comment = []byte(tail)
+		e.event.head_comment = []byte(node.HeadComment)
+		e.emit()
+
+		// The tail logic below moves the foot comment of prior keys to the following key,
+		// since the value for each key may be a nested structure and the foot needs to be
+		// processed only the entirety of the value is streamed. The last tail is processed
+		// with the mapping end event.
+		var tail string
+		for i := 0; i+1 < len(node.Content); i += 2 {
+			k := node.Content[i]
+			foot := k.FootComment
+			if foot != "" {
+				kopy := *k
+				kopy.FootComment = ""
+				k = &kopy
+			}
+			e.node(k, tail)
+			tail = foot
+
+			v := node.Content[i+1]
+			e.node(v, "")
+		}
+
+		yaml_mapping_end_event_initialize(&e.event)
+		e.event.tail_comment = []byte(tail)
+		e.event.line_comment = []byte(node.LineComment)
+		e.event.foot_comment = []byte(node.FootComment)
+		e.emit()
+
+	case AliasNode:
+		yaml_alias_event_initialize(&e.event, []byte(node.Value))
+		e.event.head_comment = []byte(node.HeadComment)
+		e.event.line_comment = []byte(node.LineComment)
+		e.event.foot_comment = []byte(node.FootComment)
+		e.emit()
+
+	case ScalarNode:
+		value := node.Value
+		if !utf8.ValidString(value) {
+			if tag == binaryTag {
+				failf("explicitly tagged !!binary data must be base64-encoded")
+			}
+			if tag != "" {
+				failf("cannot marshal invalid UTF-8 data as %s", shortTag(tag))
+			}
+			// It can't be encoded directly as YAML so use a binary tag
+			// and encode it as base64.
+			tag = binaryTag
+			value = encodeBase64(value)
+		}
+
+		style := yaml_PLAIN_SCALAR_STYLE
+		switch {
+		case node.Style&DoubleQuotedStyle != 0:
+			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+		case node.Style&SingleQuotedStyle != 0:
+			style = yaml_SINGLE_QUOTED_SCALAR_STYLE
+		case node.Style&LiteralStyle != 0:
+			style = yaml_LITERAL_SCALAR_STYLE
+		case node.Style&FoldedStyle != 0:
+			style = yaml_FOLDED_SCALAR_STYLE
+		case strings.Contains(value, "\n"):
+			style = yaml_LITERAL_SCALAR_STYLE
+		case forceQuoting:
+			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+		}
+
+		e.emitScalar(value, node.Anchor, tag, style, []byte(node.HeadComment), []byte(node.LineComment), []byte(node.FootComment), []byte(tail))
+	}
+}