Replace lodash 'defaults' usage with ES6 Spread initializer

packages/babel-cli/src/babel/dir.js

@@ -1,6 +1,5 @@
 // @flow
 
-import defaults from "lodash/defaults";
 import debounce from "lodash/debounce";
 import { sync as makeDirSync } from "make-dir";
 import slash from "slash";
@@ -48,15 +47,10 @@ export default async function ({
     const dest = getDest(relative, base);
 
     try {
-      const res = await util.compile(
-        src,
-        defaults(
-          {
-            sourceFileName: slash(path.relative(dest + "/..", src)),
-          },
-          babelOptions,
-        ),
-      );
+      const res = await util.compile(src, {
+        sourceFileName: slash(path.relative(dest + "/..", src)),
+        ...babelOptions,
+      });
 
       if (!res) return FILE_TYPE.IGNORED;
 

packages/babel-cli/src/babel/file.js

@@ -1,8 +1,8 @@
 // @flow
 
 import convertSourceMap from "convert-source-map";
-import defaults from "lodash/defaults";
 import sourceMap from "source-map";
+import defaults from "lodash/defaults";
 import slash from "slash";
 import { sync as makeDirSync } from "make-dir";
 import path from "path";
@@ -127,16 +127,10 @@ export default async function ({
   async function stdin(): Promise<void> {
     const code = await readStdin();
 
-    const res = await util.transform(
-      cliOptions.filename,
-      code,
-      defaults(
-        {
-          sourceFileName: "stdin",
-        },
-        babelOptions,
-      ),
-    );
+    const res = await util.transform(cliOptions.filename, code, {
+      sourceFileName: "stdin",
+      ...babelOptions,
+    });
 
     output([res]);
   }