lxd: always remove existing device for project folder

[kalikiana]

As a follow-up on #1483 this change removes an existing device for the project folder.

[sergiusens]

Looks good, the tests are getting harder to follow though. We might want to start trimming down what we expect from the tests and have sane defaults for things like FakeLXD().name and so on to not need to set them and unset them for the odd cases.

@ElOpio mind testing this?

[kalikiana]

@sergiusens I think you may have misunderstood how the test works. FakeLXD gets values like name and status from the mock commands that are executed. So there's no need to set anything. However, this particular test fakes an existing state of FakeLXD without any commands. If you prefer, the test could actually execute commands to create a container.

[kyrofa]

@kalikiana I think what @sergiusens means is that there are a lot of container tests in here all mocking similar things. Perhaps this would be a good opportunity to refactor these tests to have a common base class that extracts the common mocks, which will increase readability for all of them.

[come-maiz]

I tested multiple container builds with this branch. They all worked, and the change looks good to me too.

I agree that the tests code be simplified if we skip some assertions. Like the message Network connection established is not relevant for this test, so it could be removed. Or at least, hidden in a helper method.