CS: added method visibility
Added phpunit dependency to composer.json
Tidy up of tests

- Fixed visibility for setUp() method.
- Make all tests extend DoctrineTestCase.
- Escaped backslash in namespace strings.
Deleted DoctrineTestCase and added phpunit to .travis.yml
Used single quotes in namespace strings
Replaced double backslash with single backslash in namespace strings
Merge pull request #31 from vilartoni/master

CS fixes and tidy up of tests