add pretty user urls

* rerouted Project#tips and Project#deposits to Tips#index and Deposits#index
* added TipsController#load_project method
* added pretty user paths for #tips and #show
* added pretty user paths tests
* added	features/step_definitions/users_steps.rb
* added features/view_tips.feature

NOTE:
TipsController#load_project method is nearly identical to ProjectsController#load_project - they could probably be refactored into ApplicationController method