Skip ci for release commands that don't touch CI-able files (#1703)
Skip ci for release commands that don't touch CI-able files (#1703)

This works for Travis and Appveyor

https://docs.travis-ci.com/user/customizing-the-build#Skipping-a-build
https://www.appveyor.com/docs/how-to/filtering-commits/#skip-directive-in-commit-message

[skip ci]
boemmels/ponyc,Theodus/ponyc,CausalityLtd/ponyc,sgebbie/ponyc,cquinn/ponyc,Theodus/ponyc,ponylang/ponyc,Perelandric/ponyc,Praetonus/ponyc,Praetonus/ponyc,jemc/ponyc,Perelandric/ponyc,Theodus/ponyc,jemc/ponyc,CausalityLtd/ponyc,kulibali/ponyc,Perelandric/ponyc,sgebbie/ponyc,mkfifo/ponyc,cquinn/ponyc,cquinn/ponyc,dipinhora/ponyc,mkfifo/ponyc,mkfifo/ponyc,dipinhora/ponyc,boemmels/ponyc,Praetonus/ponyc,boemmels/ponyc,kulibali/ponyc,Perelandric/ponyc,CausalityLtd/ponyc,Theodus/ponyc,kulibali/ponyc,boemmels/ponyc,kulibali/ponyc,jemc/ponyc,sgebbie/ponyc,Praetonus/ponyc,Perelandric/ponyc,sgebbie/ponyc,Theodus/ponyc,mkfifo/ponyc,ponylang/ponyc,boemmels/ponyc,mkfifo/ponyc,ponylang/ponyc,dipinhora/ponyc,sgebbie/ponyc,cquinn/ponyc