Reduce rubocop offenses and don't include activeadmin models by default

Reduced the Cyclomatic complexity.
#330 By default didn't annotate activeadmin models.
This close #330

Fix the link to rubygems

Add ruby head to travis and integrate with rubocop 

Added coveralls and code climate gems.

# Conflicts:
#	Gemfile

Support hide_limit_column_types options in annotate_models.rake

Added Simplecov.

Added Active admin models.

Do not annotate controllers, helpers and scaffolds by default (revert to behavior from previous version)

Add :ignore_routes option to skip routes which should not be annotated based on regex

fix code markup in docs

Run tests by Ruby 2.3.0

Support "routes" => "true" in auto_annotate_models.rake, #245

Fix ruby wanings