Retain window to fix test. Do not debug while testing.

[babbage]

Disabling debugging while testing enables tests to be run from Xcode as well as via the command line. This commit also fixes a test that was failing because the view was being added to a window that was being deallocated before the test condition was examined.

[Antondomashnev]

@babbage thanks for your active help with PR. Unfortunately, I don't have much time to work on that project recently. Would you like me to add you as a collaborator?

[babbage]

Re being added as a collaborator, your call I guess. My ability to contribute is likely to be in sporadic leaps, where I make some changes like this and then may not be back for some time! :) So it would be variable whether I would necessarily be much assistance in reviewing pull requests from other people, though I might see them and be able to contribute sometimes. If it makes things easier for you, happy to go with what works for you. Let me know in that case what pull/merge process you'd want to see followed, if any different from the current default one.

I am actively using FBSnapshotsViewer as a tool so certainly motivated to see it continue to be useful.

[Antondomashnev]

@babbage I found it hard for myself to actively participate in the project while I'm not using it now on a daily basis. So I think if you're using it and motivated to help, it's a perfect match to add you as a collaborator :)

[Antondomashnev]

@babbage invitation has been sent 🚀 Feel free to rebase and squash it into the master after you accept the invitation.

[Antondomashnev]

@babbage Regarding the PR process there is no actually one, I prefer squashing commits into one and rebase it into master, but let me know if you have any objection about it.