Update Babel

package.json

@@ -44,19 +44,19 @@
   },
   "dependencies": {},
   "devDependencies": {
-    "@babel/core": "7.6.2",
-    "@babel/plugin-transform-flow-strip-types": "7.4.4",
-    "@babel/polyfill": "7.6.0",
-    "@babel/preset-env": "7.6.2",
-    "@babel/register": "7.6.2",
+    "@babel/core": "7.8.3",
+    "@babel/plugin-transform-flow-strip-types": "7.8.3",
+    "@babel/polyfill": "7.8.3",
+    "@babel/preset-env": "7.8.3",
+    "@babel/register": "7.8.3",
     "babel-eslint": "10.0.3",
     "chai": "4.2.0",
     "cspell": "4.0.44",
     "dtslint": "2.0.5",
     "eslint": "6.8.0",
     "eslint-plugin-flowtype": "4.6.0",
     "eslint-plugin-import": "2.20.0",
-    "flow-bin": "0.116.0",
+    "flow-bin": "0.116.1",
     "mocha": "7.0.0",
     "nyc": "15.0.0",
     "prettier": "1.19.1"

src/type/definition.js

@@ -347,13 +347,16 @@ export function assertAbstractType(type: mixed): GraphQLAbstractType {
  *     })
  *
  */
+// FIXME: workaround to fix issue with Babel parser
+/* ::
 declare class GraphQLList<+T: GraphQLType> {
   +ofType: T;
   static <T>(ofType: T): GraphQLList<T>;
   // Note: constructors cannot be used for covariant types. Drop the "new".
   constructor(ofType: GraphQLType): void;
 }
-// eslint-disable-next-line no-redeclare
+*/
+
 export function GraphQLList(ofType) {
   if (this instanceof GraphQLList) {
     this.ofType = assertType(ofType);
@@ -395,13 +398,16 @@ defineToJSON(GraphQLList);
  *
  * Note: the enforcement of non-nullability occurs within the executor.
  */
+// FIXME: workaround to fix issue with Babel parser
+/* ::
 declare class GraphQLNonNull<+T: GraphQLNullableType> {
   +ofType: T;
   static <T>(ofType: T): GraphQLNonNull<T>;
   // Note: constructors cannot be used for covariant types. Drop the "new".
   constructor(ofType: GraphQLType): void;
 }
-// eslint-disable-next-line no-redeclare
+*/
+
 export function GraphQLNonNull(ofType) {
   if (this instanceof GraphQLNonNull) {
     this.ofType = assertNullableType(ofType);