Remove support for Ruby 2.0

Ruby 2.0 is EOL. We should only support currently Ruby releases. I'd remove support for 2.1 as well, but that's what ChefDK ships with so we can't.

.travis.yml

@@ -2,7 +2,6 @@ sudo: false
 language: ruby
 cache: bundler
 rvm:
-  - 2.0
   - 2.1
   - 2.2
   - 2.3.0

README.md

@@ -1,21 +1,26 @@
 # Foodcritic
-[![Build Status](https://travis-ci.org/acrmp/foodcritic.svg?branch=master)](https://travis-ci.org/acrmp/foodcritic)
-[![Gem Version](https://badge.fury.io/rb/foodcritic.svg)](http://badge.fury.io/rb/foodcritic)
 
-Foodcritic is a lint tool for Chef cookbooks. It requires Ruby 2.0.0+.
+[![Build Status](https://travis-ci.org/acrmp/foodcritic.svg?branch=master)](https://travis-ci.org/acrmp/foodcritic) [![Gem Version](https://badge.fury.io/rb/foodcritic.svg)](http://badge.fury.io/rb/foodcritic)
+
+Foodcritic is a lint tool for Chef cookbooks. It requires Ruby 2.1.0+.
 
 # Homepage
-[http://foodcritic.io/](http://foodcritic.io/)
+
+<http://foodcritic.io/>
 
 # Building
 
-    $ bundle install
-    $ bundle exec rake
+```
+$ bundle install
+$ bundle exec rake
+```
 
 # Continuous Integration
+
 [Foodcritic on Travis CI](http://travis-ci.org/acrmp/foodcritic)
 
 # License
+
 MIT - see the accompanying [LICENSE](https://github.com/acrmp/foodcritic/blob/master/LICENSE) file for details.
 
 # Changelog

foodcritic.gemspec

@@ -10,7 +10,7 @@ Gem::Specification.new do |s|
   s.homepage = 'http://foodcritic.io'
   s.license = 'MIT'
   s.executables << 'foodcritic'
-  s.required_ruby_version = ">= 2.0.0"
+  s.required_ruby_version = '>= 2.1.0'
   s.add_dependency('cucumber-core', '>= 1.3')
   s.add_dependency('nokogiri', '>= 1.5', '< 2.0')
   s.add_dependency('rake')