use I18n errors.format key to generate field error message
Add required class to controler-group.

This makes it possible to use CSS to show witch parts of the form
are required.
Fix so that PresenceValidator results in a control-group geting a required class
Merge pull request #88 from bjornblomqvist/required_marker

Add required class to controler-group.
Fixes the travis build failure
Merge pull request #89 from bjornblomqvist/i18n_error_format

I18n error format
Change bootstrap_button_tag, bootstrap_submit_tag, and bootstrap_cancel_tag to accept custom CSS classes.
Merge pull request #93 from trevorsmith/master

Change button tags to accept custom CSS classes.
Remove .rbenv-version
Remove support 1.8
Add color to rspec output on Travis
Remove legacy code
Update CHANGELOG [ci skip]
allow per radio options in radio_buttons
Merge pull request #95 from ouvrages/per_radio_options

allow per radio options in radio_buttons
added a class on the error message span
Merge pull request #96 from ouvrages/error_class

added a class on the error message span
make radio_buttons match collection_radio_buttons
Merge pull request #94 from sshaw/rails_extra_fix

Rails extra fix
Release 4.0.1