We should replace coverall by codecov. @aabadie Just did it for joblib, and it works much better:

• [MRG] Setup integration with codecov (and remove coveralls) joblib/joblib#492
• [MRG+1] activate coverage also with python 2.7 joblib/joblib#493
  In particular, the merging of the different coverage is very nice.

Related: #7787