Turn of MacOS builds
Turn of MacOS builds

TravisCI MacOS builds have been having a lot of issues lately and are
way way behind.

Praetonus/ponyc,CausalityLtd/ponyc,Theodus/ponyc,CausalityLtd/ponyc,Praetonus/ponyc,ponylang/ponyc,Theodus/ponyc,kulibali/ponyc,sgebbie/ponyc,Theodus/ponyc,sgebbie/ponyc,sgebbie/ponyc,Theodus/ponyc,kulibali/ponyc,dipinhora/ponyc,cquinn/ponyc,dipinhora/ponyc,cquinn/ponyc,cquinn/ponyc,Praetonus/ponyc,Praetonus/ponyc,ponylang/ponyc,Theodus/ponyc,dipinhora/ponyc,cquinn/ponyc,sgebbie/ponyc,jemc/ponyc,CausalityLtd/ponyc,sgebbie/ponyc,ponylang/ponyc,jemc/ponyc,jemc/ponyc,kulibali/ponyc,kulibali/ponyc