No working appveyor config

[mohawk2]

I have made a working Travis config. I would like a working appveyor config now. It seems AppVeyor offer MinGW and various Visual Studio installations in their standard build. I would like as many of the modern-ish Windows possibilities being tested.

Unfortunately getting MSVC into the path for command-line stuff has defeated me. The closest I have got is using vcvarsall.bat (from https://stackoverflow.com/questions/42855857/how-to-find-ms-c-c-compilers-in-appveyor), but it is saying it can't find the 'include' dirs, and indeed the winnt\microsft\vpp40\mk.cmd failed because it couldn't find headers.

@bulk88 @kmx Can you help with this at all?

[bulk88]

https://help.appveyor.com/discussions/kb/48-vs2017 ????