Edit text in Coupons & Membership + Drop down

Text edits to highlight coupon value and to introduce  concept of
Startup Pack instead of just coupons
travis: tweak cache
MembershipRegistrationForm.save refactored to have a single exit point
improve regsitering_for_membership_spec
remove the .dropdown-menu gunk from theme.css and header.css
events tab jquery selector is more specific
gem bootstrap-select-rails
/events can be filtered by organizer
Link "Blog" in nav to blog.startupvictoria.com.au

For now, until we work out Heroku routing to direct to /blog/
Make signup buttons green! (instead of red)
Update committees.html.haml

Remove Gala dinner link in Committee page