Improve handling a missing .xccoverage file

[ffittschen]

Hi, when there are failing unittests, there won't be a .xccoverage file generated by Xcode. Therefore, the error raised by xcov will be passed through to Danger resulting in Danger exiting with status code 1 instead of 0. This causes that danger will only print a quite generic error message instead of the rest of the report:

In case the xcode_summary step is used, the rest of the report might even contain the failed unittests, which are now hidden to the contributors.

What do you think about adding a rescue statement to danger-xcov to handle the error gracefully and print the error message as failure in the danger report? I can create a PR if you agree with this idea.

[yhkaplan]

I for one would enjoy this!

[Kaspik]

@ffittschen Please do! :)

[ismetanin]

That would be really convenient