fix(prettier): Properly handle lint-stage files (#6970)

Now handles top level files and recursive files in folders.

Set max line length to be 100

spec/NullCacheAdapter.spec.js

@@ -1,7 +1,6 @@
-const NullCacheAdapter = require('../lib/Adapters/Cache/NullCacheAdapter')
-  .default;
+const NullCacheAdapter = require('../lib/Adapters/Cache/NullCacheAdapter').default;
 
-describe('NullCacheAdapter', function() {
+describe('NullCacheAdapter', function () {
   const KEY = 'hello';
   const VALUE = 'world';
 
@@ -11,12 +10,7 @@ describe('NullCacheAdapter', function() {
     });
 
     // Verify all methods return promises.
-    Promise.all([
-      cache.put(KEY, VALUE),
-      cache.del(KEY),
-      cache.get(KEY),
-      cache.clear(),
-    ]).then(() => {
+    Promise.all([cache.put(KEY, VALUE), cache.del(KEY), cache.get(KEY), cache.clear()]).then(() => {
       done();
     });
   });