added ruby version to gemfile to fix travis build
added ruby version to gemfile to fix travis build

bikeindex/bike_index,bikeindex/bike_index,Loos/bike_index,realchrisolin/bike_index,realchrisolin/bike_index,bikeindex/bike_index,realchrisolin/bike_index,Loos/bike_index,AWildColin/bike_index,realchrisolin/bike_index,AWildColin/bike_index,AWildColin/bike_index,Loos/bike_index,bikeindex/bike_index