Don't fail the build on coveralls upload
Don't fail the build on coveralls upload

If we can't upload to coveralls, don't fail the build.

Goveralls and Coveralls have been a little flaky and started throwing
http 422 errors, although I still see coverage being reported.

It's best in the interim to ignore these, although this should be
removed in future when the service is more stable

Signed-off-by: Dave Tucker <f7e663289261bf5663f14748dd0817050df83f40@docker.com>

AkihiroSuda/docker,cpuguy83/docker,flavio/docker,nawawi/docker,Mokolea/docker,gnailuy/docker,bearstech/moby,thaJeztah/docker,bearstech/moby,jameszhan/docker,jimjag/docker,AkihiroSuda/docker,trebonian/docker,paralin/docker,vdemeester/docker,cpuguy83/docker,flavio/docker,paralin/docker,Ramzec/docker,AkihiroSuda/docker,mahak/docker,yosifkit/docker,jthelin/docker,konstruktoid/docker-upstream,Mokolea/docker,docker/docker,yosifkit/docker,Mokolea/docker,moul/docker,jameszhan/docker,docker/docker,moul/docker,vdemeester/docker,trebonian/docker,bearstech/moby,nalind/docker,jimjag/docker,jthelin/docker,paralin/docker,mahak/docker,jimjag/docker,mahak/docker,mahak/docker,moby/moby,nawawi/docker,gnailuy/docker,moby/moby,konstruktoid/docker-upstream,trebonian/docker,moul/docker,nawawi/docker,nalind/docker,trebonian/docker,yosifkit/docker,cpuguy83/docker,cpuguy83/docker,moul/docker,moby/moby,docker/docker,Ramzec/docker,flavio/docker,nalind/docker,vdemeester/docker,AkihiroSuda/docker,paralin/docker,flavio/docker,djs55/docker,djs55/docker,gnailuy/docker,jameszhan/docker,djs55/docker,nalind/docker,thaJeztah/docker,Mokolea/docker,jimjag/docker,Ramzec/docker,Ramzec/docker,yosifkit/docker,nawawi/docker,konstruktoid/docker-upstream,moby/moby,gnailuy/docker,thaJeztah/docker,bearstech/moby,konstruktoid/docker-upstream,thaJeztah/docker