Add additional files to Appveyor skip list (#1766)
Add additional files to Appveyor skip list (#1766)

There's no reason to run an Appveyor CI run for any of
these files changing.

Note according to Appveyor folks

'**/*.md' should match ANY .md files. We should verify that
turns out to be true. I'll keep an eye out for that. Same for
'**/*.txt'
ponylang/ponyc,Praetonus/ponyc,cquinn/ponyc,boemmels/ponyc,Perelandric/ponyc,kulibali/ponyc,sgebbie/ponyc,mkfifo/ponyc,mkfifo/ponyc,CausalityLtd/ponyc,Theodus/ponyc,dipinhora/ponyc,mkfifo/ponyc,Perelandric/ponyc,boemmels/ponyc,kulibali/ponyc,jemc/ponyc,Perelandric/ponyc,dipinhora/ponyc,boemmels/ponyc,mkfifo/ponyc,jemc/ponyc,jemc/ponyc,dipinhora/ponyc,cquinn/ponyc,Theodus/ponyc,ponylang/ponyc,Theodus/ponyc,Praetonus/ponyc,sgebbie/ponyc,boemmels/ponyc,CausalityLtd/ponyc,kulibali/ponyc,Perelandric/ponyc,sgebbie/ponyc,ponylang/ponyc,mkfifo/ponyc,kulibali/ponyc,boemmels/ponyc,CausalityLtd/ponyc,Theodus/ponyc,Perelandric/ponyc,Praetonus/ponyc,Theodus/ponyc,sgebbie/ponyc,cquinn/ponyc,cquinn/ponyc,sgebbie/ponyc,Praetonus/ponyc