Change to TestModule.cs.

Sets the Categories property of the PostViewModel to be the Categories of the TestModule, not the categories of the Post.
Add new Categories Property

Adds new categories property on the PostViewModel and updates the TestModule to use it.
Update to Categories

- Renames the BaseViewModel Category property to AllCategories.
- Renames the PostViewModel Category property to Categories
- Updates the usages
Merge pull request #79 from ritasker/categories

Support for All Categories on the base view model.