Moved main code into then() for actual promise resolution

src/beautifiers/rubocop.coffee

@@ -33,7 +33,6 @@ module.exports = class Rubocop extends Beautifier
       rubocopPath = paths.find((p) -> p and path.isAbsolute(p)) or "rubocop"
       @verbose('rubocopPath', rubocopPath)
       @debug('rubocopPath', rubocopPath, paths)
-    )
 
       # Find or generate a config file if non exists
       configFile = @findFile(path.dirname(fullPath), ".rubocop.yml")
@@ -65,3 +64,4 @@ module.exports = class Rubocop extends Beautifier
         result = stdout.split("====================\n")
         result[result.length - 1]
       )
+    )