Move coveralls build to go tip build, which is allowed to fail.
Move coveralls build to go tip build, which is allowed to fail.

coveralls.io is really unstable.

adfinis-forks/aptly,aptly-dev/aptly,adfinis-forks/aptly,bsundsrud/aptly,ceocoder/aptly,vincentbernat/aptly,gdbdzgd/aptly,adfinis-forks/aptly,ceocoder/aptly,seaninspace/aptly,bsundsrud/aptly,smira/aptly,neolynx/aptly,sobczyk/aptly,gearmover/aptly,gdbdzgd/aptly,jola5/aptly,bankonme/aptly,bankonme/aptly,vincentbernat/aptly,smira/aptly,ceocoder/aptly,scalp42/aptly,seaninspace/aptly,scalp42/aptly,aptly-dev/aptly,gearmover/aptly,scalp42/aptly,bankonme/aptly,neolynx/aptly,seaninspace/aptly,sobczyk/aptly,aptly-dev/aptly,jola5/aptly,jola5/aptly,gdbdzgd/aptly,gearmover/aptly,sobczyk/aptly,neolynx/aptly,vincentbernat/aptly,bsundsrud/aptly,smira/aptly