Removed the devise and oauth gem from the Gemfile

Johnathan will be implementing these gems and they were unnecessary for the time being.
Created the models/migrations for:
Links
Folders
Folder_Links (join table between the folders and links)
Updated database schema image

Now folder_link model includes a user_id. This will be used to see if a link within a folderwas added by yourself (user_id would eq your id) or from a friend (user_id would eq the id of whoever sent it to you).
Merge pull request #1 from Onaracs/chore/folder_link_model_setup

Chore/folder link model setup