Migrations aren't associative

Considering the following migrations scheme: -(a) migrations from zero to 2.8.4 followed by migrations from 2.8.4 to 2.8.5 -(b) migrations from zero to 2.8.5

(a) is ok whereas (b) isn't :( digging a bit into this showed me that most likely we're missing some inter-apps dependency when relying on auto migrations generated by Django.

For instance we dont want the migration that removes the api.Laboratory stuffs to run before the migration that suppresses the references to api.Laboratory in the building models.

This patch fix the (b) case by adding some obviously missing deps.