Fixed env scope for RequestParser

Parser instances should be taken from `request.env` not `env`, the
old approach worked in production but interfered with unit testing.
Fixed warden instance retrieval in UnauthCntrllr

Similar to 88f1e811d83, Warden instances should be taken from
`request.env`, not just `env`.
Specs for MixinController and OcciModelController

Added basic specs for another batch of controllers, still WIP