Add CORS support
Allow only whitelist domains for cors
Merge branch 'master' into rack-cors
Merge branch 'master' into rack-cors

Conflicts:
	Gemfile.lock
Merge branch 'master' into rack-cors

Conflicts:
	.env.example
	Gemfile.lock
	config/application.rb
- Bump apitome
- Add apitome javascript and styles
- Move cors config to rack cors initializer
- Allow to set list of allowed hosts for request
Disable ruby lever warning for bin/rspec command
Merge branch 'master' into rack-cors
Add kaminari gem
Add collection serializer
Merge branch 'examples' into implement-pagination-examples

* examples:
  Inherit post and comment serializers from application serializer
  Use rails_helper instead of spec_helper for posts and comments acceptances
  Use V1 instead of Api::V1
  Update rspec doc api for versioning
  Use v1 prefix in the url for api versioning
  Generate rspec api docs
  Use post and comment root elements on specs
  Separate posts and comments seeds
  Fix rubocop warnings
  Add posts and comments to seeds
  Add posts and comments to examples branch after merge with master
Use collection serializer instead default array serializer
Add specs to check meta info on response
Generate api rspec docs
Correctly pass arguments for rack cors origings
Use be_a_json_with_pagination_represenation_of on post spec
Generate rspec api docs
Fix typo on comment spec
Remove condition from CollectionSerializer