text: Title: Travis CI fails for contributor PRs
  Body: > <a href="https://github.com/dlmiddlecote"><img align="left" height="50" src="https://avatars0.githubusercontent.com/u/9053880?v=4"></a>        An issue by [dlmiddlecote](https://github.com/dlmiddlecote) at _2019-07-09 23:00:41+00:00_
  > Original URL: https://github.com/zalando-incubator/kopf/issues/138
  > &nbsp;
  
  ## Expected Behavior
  Build passes if it should, i.e. if all tests pass.
  
  ## Actual Behavior
  Tests pass but build fails because the coveralls command fails, see [here](https://travis-ci.org/dlmiddlecote/kopf/jobs/556541531).
  
  ### Side Note
  Tags also build in forks, which could lead to versions of the library being uploaded to pupils.
  
  ---
  
  > <a href="https://github.com/dlmiddlecote"><img align="left" height="30" src="https://avatars0.githubusercontent.com/u/9053880?v=4"></a>            Commented by [dlmiddlecote](https://github.com/dlmiddlecote) at _2019-07-14 14:21:20+00:00_
  > &nbsp;
  
  Solution to this is to turn on coveralls support for kopf fork repo.