Fix parallel testing on ci

See merge request !330

These will return the paths based on whether it's a CI run
or a standard run.

Refactor update creation api

See merge request !327

The original logic would get the first item of the experiment name
which matches the user name. However, the name variable in that case
contains the name of the fork, not the fully qualified name. To fix
that, directly use the username variable.

Also add modifiable check for update/destroy end point.

This will allow to remove mixins that where going special
permission management.

Removing these mixins will allow for more flexibility with
regard to permission management.

IsAuthor requires that the user be authenticated so
use the corresponding base class.

This allows to remove the custom get method

This view only concerns one object at a time

This will allow to log the exceptions comming from
DRF in case they cannot be properly propagated back
to the user.

This will allow the use of model managers.

It was a JSONField however it should be a CharField.
It worked because the DRF JSONField does not actually
do type checks so a string can be dumped and it passes
the validation successfully.

It was a JSONField however it should be a CharField.
It worked because the DRF JSONField does not actually
do type checks so a string can be dumped and it passes
the validation successfully.