Errors when running unit tests

[pli888]

There are sometimes error messages when running unit tests in the dev environment which were observed when reviewing PR #1987.

To reproduce the problem:

1. Run ./up.sh to start dev GigaDB instance.
2. Run RelationDAOTest unit test:

docker-compose run --rm test ./vendor/codeception/codeception/codecept run unit RelationDAOTest
1) RelationDAOTest: Itshould add reciprocal relation | #0
 Test  tests/unit/RelationDAOTest.php:testItshouldAddReciprocalRelation
                                                                           
  [PHPUnit_Framework_Exception] Trying to get property 'id' of non-object  
                                                                           
#1  /var/www/protected/models/RelationDAO.php:64
#2  /var/www/tests/unit/RelationDAOTest.php:65
#3  RelationDAOTest->testItshouldAddReciprocalRelation

However, running all unit tests by executing docker-compose run --rm test ./vendor/codeception/codeception/codecept run unit will allow RelationDAOTest to pass. If you then run docker-compose run --rm test ./vendor/codeception/codeception/codecept run unit RelationDAOTest then this will pass too.

Feels like running docker-compose run --rm test ./vendor/codeception/codeception/codecept run unit makes docker-compose run --rm test ./vendor/codeception/codeception/codecept run unit RelationDAOTest use test data in protected/tests/fixtures. If you execute docker-compose run --rm test ./vendor/codeception/codeception/codecept run unit RelationDAOTest immediately after ./up.sh then dev data is used in unit tests which may be related to why it was sometimes failing for me.