diff --git a/vendor/github.com/spf13/cobra/zsh_completions.go b/vendor/github.com/spf13/cobra/zsh_completions.go
new file mode 100644
index 0000000..889c22e
--- /dev/null
+++ b/vendor/github.com/spf13/cobra/zsh_completions.go
@@ -0,0 +1,126 @@
+package cobra
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+)
+
+// GenZshCompletionFile generates zsh completion file.
+func (c *Command) GenZshCompletionFile(filename string) error {
+	outFile, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer outFile.Close()
+
+	return c.GenZshCompletion(outFile)
+}
+
+// GenZshCompletion generates a zsh completion file and writes to the passed writer.
+func (c *Command) GenZshCompletion(w io.Writer) error {
+	buf := new(bytes.Buffer)
+
+	writeHeader(buf, c)
+	maxDepth := maxDepth(c)
+	writeLevelMapping(buf, maxDepth)
+	writeLevelCases(buf, maxDepth, c)
+
+	_, err := buf.WriteTo(w)
+	return err
+}
+
+func writeHeader(w io.Writer, cmd *Command) {
+	fmt.Fprintf(w, "#compdef %s\n\n", cmd.Name())
+}
+
+func maxDepth(c *Command) int {
+	if len(c.Commands()) == 0 {
+		return 0
+	}
+	maxDepthSub := 0
+	for _, s := range c.Commands() {
+		subDepth := maxDepth(s)
+		if subDepth > maxDepthSub {
+			maxDepthSub = subDepth
+		}
+	}
+	return 1 + maxDepthSub
+}
+
+func writeLevelMapping(w io.Writer, numLevels int) {
+	fmt.Fprintln(w, `_arguments \`)
+	for i := 1; i <= numLevels; i++ {
+		fmt.Fprintf(w, `  '%d: :->level%d' \`, i, i)
+		fmt.Fprintln(w)
+	}
+	fmt.Fprintf(w, `  '%d: :%s'`, numLevels+1, "_files")
+	fmt.Fprintln(w)
+}
+
+func writeLevelCases(w io.Writer, maxDepth int, root *Command) {
+	fmt.Fprintln(w, "case $state in")
+	defer fmt.Fprintln(w, "esac")
+
+	for i := 1; i <= maxDepth; i++ {
+		fmt.Fprintf(w, "  level%d)\n", i)
+		writeLevel(w, root, i)
+		fmt.Fprintln(w, "  ;;")
+	}
+	fmt.Fprintln(w, "  *)")
+	fmt.Fprintln(w, "    _arguments '*: :_files'")
+	fmt.Fprintln(w, "  ;;")
+}
+
+func writeLevel(w io.Writer, root *Command, i int) {
+	fmt.Fprintf(w, "    case $words[%d] in\n", i)
+	defer fmt.Fprintln(w, "    esac")
+
+	commands := filterByLevel(root, i)
+	byParent := groupByParent(commands)
+
+	for p, c := range byParent {
+		names := names(c)
+		fmt.Fprintf(w, "      %s)\n", p)
+		fmt.Fprintf(w, "        _arguments '%d: :(%s)'\n", i, strings.Join(names, " "))
+		fmt.Fprintln(w, "      ;;")
+	}
+	fmt.Fprintln(w, "      *)")
+	fmt.Fprintln(w, "        _arguments '*: :_files'")
+	fmt.Fprintln(w, "      ;;")
+
+}
+
+func filterByLevel(c *Command, l int) []*Command {
+	cs := make([]*Command, 0)
+	if l == 0 {
+		cs = append(cs, c)
+		return cs
+	}
+	for _, s := range c.Commands() {
+		cs = append(cs, filterByLevel(s, l-1)...)
+	}
+	return cs
+}
+
+func groupByParent(commands []*Command) map[string][]*Command {
+	m := make(map[string][]*Command)
+	for _, c := range commands {
+		parent := c.Parent()
+		if parent == nil {
+			continue
+		}
+		m[parent.Name()] = append(m[parent.Name()], c)
+	}
+	return m
+}
+
+func names(commands []*Command) []string {
+	ns := make([]string, len(commands))
+	for i, c := range commands {
+		ns[i] = c.Name()
+	}
+	return ns
+}