Resolve double-escaping issue with pair node key (#640)

* Resolve double-escaping issue with pair node key

* Resolve double-escaping issue with pair node key

* Added test cases for pair node key

Author: ckganesan

ast/print.go

@@ -215,7 +215,7 @@ func (n *PairNode) String() string {
 		if utils.IsValidIdentifier(str.Value) {
 			return fmt.Sprintf("%s: %s", str.Value, n.Value.String())
 		}
-		return fmt.Sprintf("%q: %s", str.String(), n.Value.String())
+		return fmt.Sprintf("%s: %s", str.String(), n.Value.String())
 	}
 	return fmt.Sprintf("(%s): %s", n.Key.String(), n.Value.String())
 }

ast/print_test.go

@@ -57,6 +57,10 @@ func TestPrint(t *testing.T) {
 		{`{}`, `{}`},
 		{`{a: b}`, `{a: b}`},
 		{`{a: b, c: d}`, `{a: b, c: d}`},
+		{`{"a": b, 'c': d}`, `{a: b, c: d}`},
+		{`{"a": b, c: d}`, `{a: b, c: d}`},
+		{`{"a": b, 8: 8}`, `{a: b, "8": 8}`},
+		{`{"9": 9, '8': 8, "foo": d}`, `{"9": 9, "8": 8, foo: d}`},
 		{`[]`, `[]`},
 		{`[a]`, `[a]`},
 		{`[a, b]`, `[a, b]`},