Merge pull request #7048 from hashicorp/b-update-hcl

Update HCL to latest version

vendor/github.com/hashicorp/hcl/.gitignore

@@ -1,9 +0,0 @@
-y.output
-
-# ignore intellij files
-.idea
-*.iml
-*.ipr
-*.iws
-
-*.test

vendor/github.com/hashicorp/hcl/.travis.yml

@@ -1,3 +0,0 @@
-sudo: false
-language: go
-go: 1.5

vendor/github.com/hashicorp/hcl/hcl/strconv/quote.go

@@ -49,7 +49,8 @@ func Unquote(s string) (t string, err error) {
 	for len(s) > 0 {
 		// If we're starting a '${}' then let it through un-unquoted.
 		// Specifically: we don't unquote any characters within the `${}`
-		// section, except for escaped quotes, which we handle specifically.
+		// section, except for escaped quotes and escaped backslashes, which we
+		// handle specifically.
 		if s[0] == '$' && len(s) > 1 && s[1] == '{' {
 			buf = append(buf, '$', '{')
 			s = s[2:]
@@ -64,10 +65,12 @@ func Unquote(s string) (t string, err error) {
 
 				s = s[size:]
 
-				// We special case escaped double quotes in interpolations, converting
-				// them to straight double quotes.
+				// We special case escaped double quotes and escaped backslashes in
+				// interpolations, converting them to their unescaped equivalents.
 				if r == '\\' {
-					if q, _ := utf8.DecodeRuneInString(s); q == '"' {
+					q, _ := utf8.DecodeRuneInString(s)
+					switch q {
+					case '"', '\\':
 						continue
 					}
 				}