travis: Use the conda-forge channel.
travis: Use the conda-forge channel.

DudLab/rank_filter,DudLab/rank_filter,nanshe-org/rank_filter,jakirkham/rank_filter,DudLab/rank_filter,jakirkham/rank_filter,nanshe-org/rank_filter,nanshe-org/rank_filter,jakirkham/rank_filter