upload tool for appveyor

[tsteven4]

I like the upload tool for travis. For appveyor I created upload_appveyor.sh, substituting in APPVEYOR variables for the TRAVIS ones. I had issues with the appveyor GitHub deployment provider keeping multiple versions of continuous release. I ended up using the tag "continous" for travis and "continuous-windows" for appveyor to keep them from stepping on each other. Of course you need bash to run it, but this is commonly done with msys64 in appveyor.yml e.g.

C:\msys64\usr\bin\bash.exe -lc "cd $env:projdir; ./tools/uploadtool/upload_appveyor.sh GPSBabelTest-$($env:APPVEYOR_BUILD_VERSION)-$($sha)-Setup.exe"

If this is of interest please let me know. It would be possible to have one script, i.e. upload.sh, work with both travis and appveyor but that would be a bit more work.

[probonopd]

Thanks @tsteven4. Since I don't use Windows nor AppVeyor myself, I cannot test nor update it, hence it's probably best if you maintain it separately.

[d1vanov]

Sorry in advance for self promotion but a while ago I wrote my own tool for uploading of artifacts to continuous releases from both Travis and AppVeyor. It's based on the logic of uploadtool.sh but works with both CI systems. It's written in golang so there's a single binary without dependencies for each platform - Linux, macOS, Windows. I've been using it for my own projects for several months now and it seems to be working ok.