diff --git a/vendor/gopkg.in/yaml.v2/scannerc.go b/vendor/gopkg.in/yaml.v2/scannerc.go
index 077fd1d..0b9bb60 100644
--- a/vendor/gopkg.in/yaml.v2/scannerc.go
+++ b/vendor/gopkg.in/yaml.v2/scannerc.go
@@ -626,30 +626,17 @@
 func yaml_parser_fetch_more_tokens(parser *yaml_parser_t) bool {
 	// While we need more tokens to fetch, do it.
 	for {
-		// Check if we really need to fetch more tokens.
-		need_more_tokens := false
-
-		if parser.tokens_head == len(parser.tokens) {
-			// Queue is empty.
-			need_more_tokens = true
-		} else {
-			// Check if any potential simple key may occupy the head position.
-			if !yaml_parser_stale_simple_keys(parser) {
+		if parser.tokens_head != len(parser.tokens) {
+			// If queue is non-empty, check if any potential simple key may
+			// occupy the head position.
+			head_tok_idx, ok := parser.simple_keys_by_tok[parser.tokens_parsed]
+			if !ok {
+				break
+			} else if valid, ok := yaml_simple_key_is_valid(parser, &parser.simple_keys[head_tok_idx]); !ok {
 				return false
+			} else if !valid {
+				break
 			}
-
-			for i := range parser.simple_keys {
-				simple_key := &parser.simple_keys[i]
-				if simple_key.possible && simple_key.token_number == parser.tokens_parsed {
-					need_more_tokens = true
-					break
-				}
-			}
-		}
-
-		// We are finished.
-		if !need_more_tokens {
-			break
 		}
 		// Fetch the next token.
 		if !yaml_parser_fetch_next_token(parser) {
@@ -678,11 +665,6 @@
 		return false
 	}
 
-	// Remove obsolete potential simple keys.
-	if !yaml_parser_stale_simple_keys(parser) {
-		return false
-	}
-
 	// Check the indentation level against the current column.
 	if !yaml_parser_unroll_indent(parser, parser.mark.column) {
 		return false
@@ -837,29 +819,30 @@
 		"found character that cannot start any token")
 }
 
-// Check the list of potential simple keys and remove the positions that
-// cannot contain simple keys anymore.
-func yaml_parser_stale_simple_keys(parser *yaml_parser_t) bool {
-	// Check for a potential simple key for each flow level.
-	for i := range parser.simple_keys {
-		simple_key := &parser.simple_keys[i]
-
-		// The specification requires that a simple key
-		//
-		//  - is limited to a single line,
-		//  - is shorter than 1024 characters.
-		if simple_key.possible && (simple_key.mark.line < parser.mark.line || simple_key.mark.index+1024 < parser.mark.index) {
-
-			// Check if the potential simple key to be removed is required.
-			if simple_key.required {
-				return yaml_parser_set_scanner_error(parser,
-					"while scanning a simple key", simple_key.mark,
-					"could not find expected ':'")
-			}
-			simple_key.possible = false
-		}
+func yaml_simple_key_is_valid(parser *yaml_parser_t, simple_key *yaml_simple_key_t) (valid, ok bool) {
+	if !simple_key.possible {
+		return false, true
 	}
-	return true
+
+	// The 1.2 specification says:
+	//
+	//     "If the ? indicator is omitted, parsing needs to see past the
+	//     implicit key to recognize it as such. To limit the amount of
+	//     lookahead required, the “:” indicator must appear at most 1024
+	//     Unicode characters beyond the start of the key. In addition, the key
+	//     is restricted to a single line."
+	//
+	if simple_key.mark.line < parser.mark.line || simple_key.mark.index+1024 < parser.mark.index {
+		// Check if the potential simple key to be removed is required.
+		if simple_key.required {
+			return false, yaml_parser_set_scanner_error(parser,
+				"while scanning a simple key", simple_key.mark,
+				"could not find expected ':'")
+		}
+		simple_key.possible = false
+		return false, true
+	}
+	return true, true
 }
 
 // Check if a simple key may start at the current position and add it if
@@ -879,13 +862,14 @@
 			possible:     true,
 			required:     required,
 			token_number: parser.tokens_parsed + (len(parser.tokens) - parser.tokens_head),
+			mark:         parser.mark,
 		}
-		simple_key.mark = parser.mark
 
 		if !yaml_parser_remove_simple_key(parser) {
 			return false
 		}
 		parser.simple_keys[len(parser.simple_keys)-1] = simple_key
+		parser.simple_keys_by_tok[simple_key.token_number] = len(parser.simple_keys) - 1
 	}
 	return true
 }
@@ -900,19 +884,33 @@
 				"while scanning a simple key", parser.simple_keys[i].mark,
 				"could not find expected ':'")
 		}
+		// Remove the key from the stack.
+		parser.simple_keys[i].possible = false
+		delete(parser.simple_keys_by_tok, parser.simple_keys[i].token_number)
 	}
-	// Remove the key from the stack.
-	parser.simple_keys[i].possible = false
 	return true
 }
 
+// max_flow_level limits the flow_level
+const max_flow_level = 10000
+
 // Increase the flow level and resize the simple key list if needed.
 func yaml_parser_increase_flow_level(parser *yaml_parser_t) bool {
 	// Reset the simple key on the next level.
-	parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{})
+	parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{
+		possible:     false,
+		required:     false,
+		token_number: parser.tokens_parsed + (len(parser.tokens) - parser.tokens_head),
+		mark:         parser.mark,
+	})
 
 	// Increase the flow level.
 	parser.flow_level++
+	if parser.flow_level > max_flow_level {
+		return yaml_parser_set_scanner_error(parser,
+			"while increasing flow level", parser.simple_keys[len(parser.simple_keys)-1].mark,
+			fmt.Sprintf("exceeded max depth of %d", max_flow_level))
+	}
 	return true
 }
 
@@ -920,11 +918,16 @@
 func yaml_parser_decrease_flow_level(parser *yaml_parser_t) bool {
 	if parser.flow_level > 0 {
 		parser.flow_level--
-		parser.simple_keys = parser.simple_keys[:len(parser.simple_keys)-1]
+		last := len(parser.simple_keys) - 1
+		delete(parser.simple_keys_by_tok, parser.simple_keys[last].token_number)
+		parser.simple_keys = parser.simple_keys[:last]
 	}
 	return true
 }
 
+// max_indents limits the indents stack size
+const max_indents = 10000
+
 // Push the current indentation level to the stack and set the new level
 // the current column is greater than the indentation level.  In this case,
 // append or insert the specified token into the token queue.
@@ -939,6 +942,11 @@
 		// indentation level.
 		parser.indents = append(parser.indents, parser.indent)
 		parser.indent = column
+		if len(parser.indents) > max_indents {
+			return yaml_parser_set_scanner_error(parser,
+				"while increasing indent level", parser.simple_keys[len(parser.simple_keys)-1].mark,
+				fmt.Sprintf("exceeded max depth of %d", max_indents))
+		}
 
 		// Create a token and insert it into the queue.
 		token := yaml_token_t{
@@ -989,6 +997,8 @@
 	// Initialize the simple key stack.
 	parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{})
 
+	parser.simple_keys_by_tok = make(map[int]int)
+
 	// A simple key is allowed at the beginning of the stream.
 	parser.simple_key_allowed = true
 
@@ -1270,7 +1280,11 @@
 	simple_key := &parser.simple_keys[len(parser.simple_keys)-1]
 
 	// Have we found a simple key?
-	if simple_key.possible {
+	if valid, ok := yaml_simple_key_is_valid(parser, simple_key); !ok {
+		return false
+
+	} else if valid {
+
 		// Create the KEY token and insert it into the queue.
 		token := yaml_token_t{
 			typ:        yaml_KEY_TOKEN,
@@ -1288,6 +1302,7 @@
 
 		// Remove the simple key.
 		simple_key.possible = false
+		delete(parser.simple_keys_by_tok, simple_key.token_number)
 
 		// A simple key cannot follow another simple key.
 		parser.simple_key_allowed = false