Ensure JSXOpeningElement does not break with single text attr on Babylon (#1229)

src/printer.js

@@ -1296,7 +1296,8 @@ function genericPrintNoParens(path, options, print, args) {
       if (
         n.attributes.length === 1 &&
         n.attributes[0].value &&
-        n.attributes[0].value.type === "Literal" &&
+        (n.attributes[0].value.type === "Literal" ||
+          n.attributes[0].value.type === "StringLiteral") &&
         typeof n.attributes[0].value.value === "string"
       ) {
         return group(

tests/jsx-newlines/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, null, ["typescript"]);
+run_spec(__dirname, null, ["babylon", "typescript"]);

tests/jsx-split-attrs/jsfmt.spec.js

@@ -1 +1 @@
-run_spec(__dirname, null, ["typescript"]);
+run_spec(__dirname, null, ["babylon", "typescript"]);