Add migration and model for regions

* Add migration to create regions table
* Add migration to add null: false to regions: name
* Create model and add post and validation specifications
Add routes and controller for regions

* Add routes for new and create
* Create regions controller and add new and create methods
* Require admin login
Add views for regions

* Add new.html.erb and render form
* Add form for creating/editing regions
* Add link to create regions to admin page
Consolidate migrations for regions table
Merge pull request #9 from elijahkim/ha-regions

Create regions

* As an admin, I can add geographic regions (Boston, NYC, Atlanta, etc) for people to post to
Create Categories

* Created Categories controller
* Modified Routes
* Created Categories model
* Put link to create categry in admin page
* Gave ability to create a category
Allow Admin to edit category

* Added def edit, def update
* User can only access show and index pages
Give admin ability to delete a category

* If admin delete link appears in category view
* Only an admin can delete
* Changed index to links of categories
Fix spacing errors
Updated Category model to not have a relation to region
Add check_admin into application controller

* Rename check_authorization to check_admin
* Move check_admin to application controller
Category name can't be null

* Changed category model to validate name presence true
* Migrated name in category table to null: :false
rolled back migration to add null: :false to name
created categories in a single migration
Combined category migrations
tracking deleted files
fixing migrations