Front page can create a user

In addition added pry and pry nav to the gem bundle. Created a few extra controllers that will be useful in the future but are blank for now.
Jess have such nice things.

Merge branch 'master' of https://github.com/thejessleigh/sinatra-flash-cards-master
hopefully adding controller files.
Incorporating latest additions from Jess

Merge branch 'master' of https://github.com/thejessleigh/sinatra-flash-cards-master
Add BCrypt to user model