Bugfix view errors for sign up

* fix the 'no method_name for nil class' error, which allowed for the 'new' route to work.
--> change instance variable to symbol in form_for
--> rebundle to fix gemfile.lock for bcrypt error
- added a create.html.erb page
- changed the create action in the users controller so that it redirected to the create.html.erb page
- added a link back to the homepage from the 'successfully signed up' page
- passed all rspec tests! yay!
- changed the new.html.erb so that it redirects correctly