added simpleform
added devise and generated relevant models for User and imported devise's provided views'
added rspec directories and initial User model skeleton
added shoulda matcher tests for User model email and password. Added a factory for User model. Added validations to User model
added circle.yml file to configure circleCI to use a newer ruby version
removed confirmable as not required
amended ruby v to comply with CircleCI format
Merge pull request #2 from oafridi/user_authentication

User authentication