Update rubocop to version 0.30.1

Author: sferik

Diff for: Gemfile.lock

@@ -177,9 +177,9 @@ GEM
       http-cookie (>= 1.0.2, < 2.0)
       mime-types (>= 1.16, < 3.0)
       netrc (~> 0.7)
-    rubocop (0.30.0)
+    rubocop (0.30.1)
       astrolabe (~> 1.3)
-      parser (>= 2.2.0.1, < 3.0)
+      parser (>= 2.2.2.1, < 3.0)
       powerpack (~> 0.1)
       rainbow (>= 1.99.1, < 3.0)
       ruby-progressbar (~> 1.4)