added chosen-rails gem
included chosen css/js libs in the manifest files
include custom styling file for chosen
added activity field to workout form with chosen styling and js
added helper method for loading anim html
added css animation stylesheet
added continue button for after selecting an activity
trigger change when page loads on workout activity field
added text align center to body id tag
decreased bottom margin on activity select field
added preview boxes on workout form page
set up association between activity and workout model
added MET value hidden form field to workout form
added hidden field for activity id on workout form
only change activity preview value if activity select field is present
added member route for activity met action
setup met action to return met value of activity when activity is select on workout form