Adding Rubocop to CI

Author: abeger

.travis.yml

@@ -1,5 +1,9 @@
 language: ruby
 rvm:
   - 2.6.5
-script:
-  - bundle exec rspec
+jobs:
+  include:
+    - script: bundle exec rspec
+      name: Testing
+    - script: bundle exec rubocop
+      name: Linting

Gemfile

@@ -6,8 +6,5 @@ git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 
 gem 'require_all'
 
-# Needed for CI
-gem 'rake'
-
 gem 'rspec'
 gem 'rubocop'