restrict ruby testing to version 2.3.3 and update gemfile

Signed-off-by: Patrick Münch <[email protected]>

Author: atomic111

.travis.yml

@@ -2,9 +2,7 @@
 language: ruby
 cache: bundler
 rvm:
-  - 2.0
-  - 2.2
-  - 2.3.1
+  - 2.3.3
 
 bundler_args: --without integration
 script: bundle exec rake

Gemfile

@@ -1,10 +1,10 @@
 source 'https://rubygems.org'
 
-gem 'rake'
-gem 'rack', '1.6.4'
-gem 'inspec', '~> 1'
-gem 'rubocop', '~> 0.44.0'
 gem 'highline', '~> 1.6.0'
+gem 'inspec', '~> 1'
+gem 'rack', '1.6.4'
+gem 'rake'
+gem 'rubocop', '~> 0.46.0'
 
 group :tools do
   gem 'github_changelog_generator', '~> 1.12.0'