Help tag rendered by #control_group method

This way is possible to have help and error messages for standalone
control_groups
Change the way that the helper is appended inside the controls div
Merge pull request #9 from carloslopes/control-group-help

Help tag rendered by #control_group method
adding a help option to one of the control group examples
adding test for secondary button
adding an 'append' option
fixing typo
version bump
adding .travis.yml config file
version bump
tweaking travis file
tweaking travis.yml file
adjust for timecop timezone handling
adding travis build status to readme. fixes #7