Added GitHub Actions configuration for CI build and test on Linux, MacOS and Windows via MinGW.
Added GitHub Actions configuration for CI build and test on Linux, MacOS and Windows via MinGW.

malloch/libmapper,radarsat1/libmapper,libmapper/libmapper,malloch/libmapper,malloch/libmapper,libmapper/libmapper,radarsat1/libmapper,malloch/libmapper,libmapper/libmapper,radarsat1/libmapper,malloch/libmapper,malloch/libmapper,radarsat1/libmapper,libmapper/libmapper,radarsat1/libmapper,libmapper/libmapper,libmapper/libmapper