Added tag and tagService classes
Added Phinx migration file for tag
Merge branches 'master' and 'tags' of github.com:phpmentoring/mentor-app into tags
Hid table setting ability from public view
Removed tag_table variable
Fixed a minor issue
Made queries slightly more compliant
Add tests for the TagService

Add some coverage for the TagService. Modifies the retrieve method
from accepting a Tag object to accepting a "name" to retrieve a
tag for consistency with the user branch.

Note: There is a class PDOTestHelper inside the test case for the
TagService which should be removed once the user branch is merged
into master.
Removed the __set because, really, it's not needed
Merge remote-tracking branch 'origin/tags' into tags
Merge branch 'tags' of github.com:phpmentoring/mentor-app into tags
Merge remote-tracking branch 'origin/master' into tags
Remove test for __set() Exception
Merge branch 'tags' of github.com:phpmentoring/mentor-app into tags
Add some exception handling for the PDO calls in TagService
Moving query variable inside the try block because it seemed weird to have it outside
Fixing tabs in TagService
Updating the docblox for the retrieve method
Added delete method to tag service
Fixing a mistake on the execute method of TagService::delete
Merge pull request #31 from phpmentoring/tags

This looks good to me - merging