Supply Repo Token when reporting test coverage to coveralls.io

[liangyuanruo]

Duplicate service job IDs from Travis during job restarts cannot pass CI due to coveralls.io error. The existing workaround is to manually trigger a new job instead of restarting an existing one.

Bad response: 422 {"message":"service_job_id (378233677) must be unique for Travis Jobs not supplying a Coveralls Repo Token","error":true}

Introduce a Coveralls repo token so that jobs can be easily restarted.

[arshadali172]

Tried 3 possible solutions:

1. Specifying COVERALLS_REPO_TOKEN as suggested here and documented here. Though, multiple comments say that a token should not even need to be specified for public repos.

2. Moving the coveralls script to after_success as suggested here.

3. Explicitly specifying the COVERALLS_SERVICE_JOB_ID as suggested here.

None worked. There are some suggestions to move to codeCov, which I suggest that we explore.

[tshuli]

Stale