fix: Disable docker log for now to fix tests

[tofumatt]

Trying this to see what happens, because these constantly "failing" tests are annoying and a bad thing–they're gonna make me think something is fine when it isn't soon.

[tofumatt]

This prevents the tests from running docker logs on Travis which seems to cause an error.

This is a stop-gap but as you can see from the test output it still runs the tests (successfully) so I think this is a good temporary fix to stop all of ours builds from constantly stating they've (falsely) failed to build.

I think this would be good to merge as ignoring failed builds is bad and having to dig into the reason builds have failed is frustrating and time-consuming, especially when we have a lot of contributor and Greenkeeper PRs to keep up with at the moment.

[tofumatt]

If someone from QA could let us know why the docker logs command is even needed that'd be great... the test output seems to still be here and the tests are run, so I'm not sure what they're for...

[muffinresearch]

r+

Would be good to understand what it was there for. Dave Hunt would probably know.

[kumar303]

docker logs is pretty essential since it helps us figure out what's going on (server side) when the py.test suite fails. I'll work on fixing it in mozilla/addons#10539