Enable functional tests and write a LoginAPI test
What does this MR do?
- configures functional tests to use our symfony kernel inside codeception
- adds a simple login API test
- describes the limits of functional testing that apply to current foodsharing code in a file next to the functional tests, hoping that people read it before they wonder why their tests don't work
How confident are you it won't break things if deployed?
Links to related issues
- added a test, or explain why one is not needed/possible...
- no unrelated changes
- asked someone for a code review
- joined #foodsharing-beta channel at https://slackin.yunity.org
- added an entry to CHANGELOG.md (description, merge request link, username(s))