[WIP] Added Orm testing

| Q             | A
| ------------- | ---
| Bug fix?      | probably
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #142
| License       | MIT
| Doc PR        | -

This is a work in progress. Currently, only mocked unit tests are done.

## Todo

 - [ ] Add ORM DbManager to symfony-cmf/Testing
 - [ ] Add Functional tests