Investigate error messages from CI runners
Every hour the CI runners are logging errors similar to the following:
May 12 06:46:04 ci gitlab-runner[21146]: time="2017-05-12T06:46:04Z" level=error msg="Runner https://code.briarproject.org/ci733e[scrubbed] is not healthy, but will be checked!" #012<nil>
May 12 06:46:04 ci gitlab-ci-multi-runner[21146]: time="2017-05-12T06:46:04Z" level=error msg="Runner https://code.briarproject.org/ci733e[scrubbed] is not healthy, but will be checked!"
May 12 06:46:04 ci gitlab-runner[21146]: time="2017-05-12T06:46:04Z" level=error msg="Checking for builds... forbidden" runner=733eb190 #012<nil>
May 12 06:46:04 ci gitlab-ci-multi-runner[21146]: time="2017-05-12T06:46:04Z" level=error msg="Checking for builds... forbidden" runner=733eb190
May 12 06:46:07 ci gitlab-runner[21146]: time="2017-05-12T06:46:07Z" level=error msg="Checking for builds... forbidden" runner=733eb190 #012<nil>
May 12 06:46:07 ci gitlab-ci-multi-runner[21146]: time="2017-05-12T06:46:07Z" level=error msg="Checking for builds... forbidden" runner=733eb190
May 12 06:46:10 ci gitlab-runner[21146]: time="2017-05-12T06:46:10Z" level=error msg="Checking for builds... forbidden" runner=733eb190 #012<nil>
May 12 06:46:10 ci gitlab-ci-multi-runner[21146]: time="2017-05-12T06:46:10Z" level=error msg="Checking for builds... forbidden" runner=733eb190
May 12 06:46:10 ci gitlab-runner[21146]: time="2017-05-12T06:46:10Z" level=error msg="Runner https://code.briarproject.org/ci733e[scrubbed] is not healthy and will be disabled!" #012<nil>
May 12 06:46:10 ci gitlab-ci-multi-runner[21146]: time="2017-05-12T06:46:10Z" level=error msg="Runner https://code.briarproject.org/ci733e[scrubbed] is not healthy and will be disabled!"