ADD: Tests. #16

Add php unit test cases.
Cases:
- Page
    - Add
    - Delete
- User
    - Add
    - Delete
    - Exists
more coming soon
ADD: Picture test case

Test create and remove.
Coming soon, test if can upload and return albums to display.
Merge branch 'master' into unittests
MODIFIED: Picture test case.

New:
- upload picture
- remove picture
- remove album
- get picture from album