Bump rubocop from 0.54.0 to 0.55.0 (#103)

Bumps [rubocop](https://github.com/bbatsov/rubocop) from 0.54.0 to 0.55.0.
- [Release notes](https://github.com/bbatsov/rubocop/releases)
- [Changelog](https://github.com/bbatsov/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v0.54.0...v0.55.0)

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

Gemfile

@@ -34,7 +34,7 @@ end
 
 group :development do
   gem 'listen', '>= 3.0.5', '< 3.2'
-  gem 'rubocop', '~> 0.54.0', require: false
+  gem 'rubocop', '~> 0.55.0', require: false
   gem 'spring'
   gem 'spring-watcher-listen', '~> 2.0.0'
   gem 'web-console', '>= 3.3.0'

Gemfile.lock

@@ -116,7 +116,7 @@ GEM
     nokogiri (1.8.2)
       mini_portile2 (~> 2.3.0)
     parallel (1.12.1)
-    parser (2.5.0.5)
+    parser (2.5.1.0)
       ast (~> 2.4.0)
     pg (0.21.0)
     popper_js (1.12.9)
@@ -157,7 +157,7 @@ GEM
     rb-inotify (0.9.10)
       ffi (>= 0.5.0, < 2)
     redis (4.0.1)
-    rubocop (0.54.0)
+    rubocop (0.55.0)
       parallel (~> 1.10)
       parser (>= 2.5)
       powerpack (~> 0.1)
@@ -246,7 +246,7 @@ DEPENDENCIES
   puma (~> 3.11)
   rails (~> 5.1.6)
   redis (~> 4.0)
-  rubocop (~> 0.54.0)
+  rubocop (~> 0.55.0)
   sass-rails (~> 5.0)
   selenium-webdriver
   slim-rails