Add gems to Gemfile

- rspec-rails
- factory_girl_rails
- faker
- capybara
- database_cleaner
- launchy
- shoulda-matchers
Install rspec
Configure spec_helper.rb
Add database_cleaner.rb file
Remove session helpers from spec_helper
feature spec (new)

- User can generate workouts
Remove difficulty and equipment from Exercises

as they are not needed (yet)
Remove difficulty and equipment from seed data

because fields were removed from database
Add bootstrap to layout file
Change page layout title to "Workout Now"
Set debugger on dev environment only