Created user authentication

* users can create accounts
* users can login
* users can logout
* users can only reach user page and profile when logged in
Merge pull request #5 from keaty/routes-models

Routes models
Created simple deck view page, updated CSS
Merge pull request #6 from reboryan/feat/card_view

Created simple deck view page, updated CSS
Merge pull request #7 from tihuan/master

add spanish deck
resolved merge conflict