Quoting; move away from AppVeyor CI

.appveyor.yml

@@ -1,26 +0,0 @@
-
-image:
-  - Visual Studio 2019
-
-configuration:
-  - Release
-
-platform:
-  - x64
-
-install:
-  - cinst wget
-  - cinst libsndfile
-
-build_script:
-  - call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64.bat"
-  - meson build "-Dextra_include_dirs=C:\Program Files\libsndfile\include" "-Dextra_lib_dirs=C:\Program Files\libsndfile\lib"
-  - ninja -C build
-  - meson test -C build
-  # Test the VC++ static library build, which is separate
-  - msbuild otherbuilds\rubberband-library.vcxproj /t:Build /p:Configuration=Release
-  # Test the .NET FFI interface build, which is again separate
-  - msbuild dotnet\rubberband.sln /t:Restore;Build
-  # And test the single-file build
-  - cl main\main.cpp single\RubberBandSingle.cpp .\src\ext\getopt\getopt.c src\ext\getopt\getopt_long.c "C:\Program Files\libsndfile\lib\sndfile.lib" /O2 /std:c++14 /D_USE_MATH_DEFINES /DNOMINMAX /EHs /I"C:\Program Files\libsndfile\include" /link /out:test_single.exe
-

.github/workflows/windows.yml

@@ -33,4 +33,9 @@ jobs:
         msbuild otherbuilds\rubberband-library.vcxproj /t:Build /p:Configuration=Release
     - name: dotnet
       run: |
-        msbuild dotnet\rubberband.sln /t:Restore;Build
+        msbuild dotnet\rubberband.sln "/t:Restore;Build"
+
+## (Commented out as cl not in path - to fix)
+#    - name: single
+#      run: |
+#        cl main\main.cpp single\RubberBandSingle.cpp .\src\ext\getopt\getopt.c src\ext\getopt\getopt_long.c "C:\Program Files\libsndfile\lib\sndfile.lib" /O2 /std:c++14 /D_USE_MATH_DEFINES /DNOMINMAX /EHs /I"C:\Program Files\libsndfile\include" /link /out:test_single.exe