Add SessionsController to get login form

SessionsController is responsible for getting rails partial login
form and posting user signup and login data
Add SessionsView

Reponsible for:
- drawing login form
- drawing signup form
- assigning dom elements to variables
Remove signup jquery soup

event listener, ajax get request, and view draw is now
encapsulated in the sessionsController.signUpListener();

sessionsController will be further abstracted by initializing
all listeners under one method