Merge pull request #5 from CerebralStorm/comp_join

Comp join
adds numerical validation
add description to competition
add extra error messages
Merge pull request #7 from CerebralStorm/activities

Activities
add modal
log activity from main page
update modal and add success message
refactors competition view logic to reduce the amount of if statements.
adds description to competition
update competition view
adds description to competition page
updates cucumber
Merge pull request #8 from CerebralStorm/activity_modal

Activity modal
merged in master