Bump RuboCop to 0.66.0

### Summary

RuboCop 0.66.0 has been released.
https://github.com/rubocop-hq/rubocop/releases/tag/v0.66.0

And rubocop-0-66 channel is available in Code Climate.
https://github.com/codeclimate/codeclimate/releases/tag/v0.84.0

RuboCop 0.66.0 fixed the false negative to indentation for
modifier. And this PR applied the auto-correction fixed by it.
https://github.com/rubocop-hq/rubocop/pull/6792

In addtion, this PR is also updating the following 4 gems that
RuboCop depends on.

- Update Psych gem ... https://github.com/rubocop-hq/rubocop/pull/6766
- Update Parser gem to 2.6.2.0 that supports Ruby 2.5.5 and 2.6.2 ...
 https://github.com/whitequark/parser/blob/v2.6.2.0/CHANGELOG.md#changelog
- Remove powerpack gem ... https://github.com/rubocop-hq/rubocop/pull/6806
- Update unicode-display_width gem ... https://github.com/rubocop-hq/rubocop/pull/6813

.codeclimate.yml

@@ -23,7 +23,7 @@ checks:
 engines:
   rubocop:
     enabled: true
-    channel: rubocop-0-63
+    channel: rubocop-0-66
 
 ratings:
   paths:

Gemfile.lock

@@ -347,14 +347,17 @@ GEM
       mini_portile2 (~> 2.4.0)
     os (1.0.0)
     parallel (1.13.0)
-    parser (2.6.0.0)
+    parser (2.6.2.0)
       ast (~> 2.4.0)
     path_expander (1.0.3)
     pg (1.1.3)
     pg (1.1.3-x64-mingw32)
     pg (1.1.3-x86-mingw32)
-    powerpack (0.1.2)
-    psych (3.0.3)
+    psych (3.1.0)
+    psych (3.1.0-java)
+      jar-dependencies (>= 0.1.7)
+    psych (3.1.0-x64-mingw32)
+    psych (3.1.0-x86-mingw32)
     public_suffix (3.0.3)
     puma (3.12.1)
     puma (3.12.1-java)
@@ -405,14 +408,14 @@ GEM
       resque (~> 1.26)
       rufus-scheduler (~> 3.2)
     retriable (3.1.2)
-    rubocop (0.63.0)
+    rubocop (0.66.0)
       jaro_winkler (~> 1.5.1)
       parallel (~> 1.10)
       parser (>= 2.5, != 2.5.1.1)
-      powerpack (~> 0.1)
+      psych (>= 3.1.0)
       rainbow (>= 2.2.2, < 4.0)
       ruby-progressbar (~> 1.7)
-      unicode-display_width (~> 1.4.0)
+      unicode-display_width (>= 1.4.0, < 1.6)
     ruby-progressbar (1.10.0)
     ruby-vips (2.0.13)
       ffi (~> 1.9)
@@ -493,7 +496,7 @@ GEM
     uber (0.1.0)
     uglifier (4.1.19)
       execjs (>= 0.3.0, < 3)
-    unicode-display_width (1.4.0)
+    unicode-display_width (1.5.0)
     useragent (0.16.10)
     vegas (0.1.11)
       rack (>= 1.0.0)

actionview/test/actionpack/abstract/abstract_controller_test.rb

@@ -229,11 +229,11 @@ def index() self.response_body = "success" end
     end
 
     class ActionMissingRespondToActionController < AbstractController::Base
-    # No actions
-    private
-      def action_missing(action_name)
-        self.response_body = "success"
-      end
+      # No actions
+      private
+        def action_missing(action_name)
+          self.response_body = "success"
+        end
     end
 
     class RespondToActionController < AbstractController::Base