Bump rubocop-rails from 2.11.3 to 2.15.2

Bumps [rubocop-rails](https://github.com/rubocop/rubocop-rails) from 2.11.3 to 2.15.2.
- [Release notes](https://github.com/rubocop/rubocop-rails/releases)
- [Changelog](https://github.com/rubocop/rubocop-rails/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop-rails@v2.11.3...v2.15.2)

---
updated-dependencies:
- dependency-name: rubocop-rails
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile

@@ -108,7 +108,7 @@ group :development do
   gem "pronto-scss", "~> 0.11.0", require: false
   gem "rubocop", "~> 1.18.4", require: false
   gem "rubocop-performance", "~> 1.11.4", require: false
-  gem "rubocop-rails", "~> 2.11.3", require: false
+  gem "rubocop-rails", "~> 2.15.2", require: false
   gem "rubocop-rspec", "~> 2.4.0", require: false
   gem "rvm1-capistrano3", "~> 1.4.0", require: false
   gem "scss_lint", "~> 0.59.0", require: false

Gemfile.lock

@@ -1,6 +1,11 @@
 GEM
-  remote: https://rubygems.org/
   remote: https://rails-assets.org/
+  specs:
+    rails-assets-leaflet (1.5.1)
+    rails-assets-markdown-it (9.0.1)
+
+GEM
+  remote: https://rubygems.org/
   specs:
     actioncable (5.2.8.1)
       actionpack (= 5.2.8.1)
@@ -145,7 +150,7 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    concurrent-ruby (1.1.9)
+    concurrent-ruby (1.1.10)
     coveralls (0.8.23)
       json (>= 1.8, < 3)
       simplecov (~> 0.16.1)
@@ -302,7 +307,7 @@ GEM
     httpi (2.4.5)
       rack
       socksify
-    i18n (1.10.0)
+    i18n (1.12.0)
       concurrent-ruby (~> 1.0)
     i18n-tasks (0.9.34)
       activesupport (>= 4.0.2)
@@ -376,7 +381,7 @@ GEM
     mini_magick (4.11.0)
     mini_mime (1.1.2)
     mini_portile2 (2.8.0)
-    minitest (5.15.0)
+    minitest (5.16.3)
     mixlib-cli (2.1.8)
     mixlib-config (3.0.9)
       tomlrb
@@ -427,10 +432,10 @@ GEM
       omniauth-oauth (~> 1.1)
       rack
     orm_adapter (0.5.0)
-    parallel (1.20.1)
+    parallel (1.22.1)
     paranoia (2.4.3)
       activerecord (>= 4.0, < 6.2)
-    parser (3.1.2.0)
+    parser (3.1.2.1)
       ast (~> 2.4.1)
     pg (1.2.3)
     pg_search (2.3.5)
@@ -460,7 +465,7 @@ GEM
     puma (4.3.12)
       nio4r (~> 2.0)
     racc (1.6.0)
-    rack (2.2.3.1)
+    rack (2.2.4)
     rack-accept (0.4.5)
       rack (>= 0.4)
     rack-protection (2.1.0)
@@ -482,8 +487,6 @@ GEM
       bundler (>= 1.3.0)
       railties (= 5.2.8.1)
       sprockets-rails (>= 2.0.0)
-    rails-assets-leaflet (1.5.1)
-    rails-assets-markdown-it (9.0.1)
     rails-dom-testing (2.0.3)
       activesupport (>= 4.2.0)
       nokogiri (>= 1.6)
@@ -498,7 +501,7 @@ GEM
       method_source
       rake (>= 0.8.7)
       thor (>= 0.19.0, < 2.0)
-    rainbow (3.0.0)
+    rainbow (3.1.1)
     rake (13.0.6)
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)
@@ -507,7 +510,7 @@ GEM
     recipient_interceptor (0.3.0)
       mail
     redcarpet (3.5.1)
-    regexp_parser (2.1.1)
+    regexp_parser (2.5.0)
     request_store (1.5.0)
       rack (>= 1.4)
     responders (3.0.1)
@@ -542,12 +545,12 @@ GEM
       rubocop-ast (>= 1.8.0, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 1.4.0, < 3.0)
-    rubocop-ast (1.9.1)
-      parser (>= 3.0.1.1)
+    rubocop-ast (1.21.0)
+      parser (>= 3.1.1.0)
     rubocop-performance (1.11.4)
       rubocop (>= 1.7.0, < 2.0)
       rubocop-ast (>= 0.4.0)
-    rubocop-rails (2.11.3)
+    rubocop-rails (2.15.2)
       activesupport (>= 4.2.0)
       rack (>= 1.1)
       rubocop (>= 1.7.0, < 2.0)
@@ -648,7 +651,7 @@ GEM
       thread_safe (~> 0.1)
     uglifier (4.2.0)
       execjs (>= 0.3.0, < 3)
-    unicode-display_width (1.7.0)
+    unicode-display_width (1.8.0)
     uniform_notifier (1.14.2)
     uuidtools (2.1.5)
     view_component (2.49.1)
@@ -763,7 +766,7 @@ DEPENDENCIES
   rspec-rails (~> 5.0)
   rubocop (~> 1.18.4)
   rubocop-performance (~> 1.11.4)
-  rubocop-rails (~> 2.11.3)
+  rubocop-rails (~> 2.15.2)
   rubocop-rspec (~> 2.4.0)
   rvm1-capistrano3 (~> 1.4.0)
   sassc-rails (~> 2.1.2)