[ci] set github CI

[inkydragon]

Build on: ubuntu, windows, macOS, win+mingw64

Fix #206

We can add more combinations if needed, for example: ubuntu+mingw64, win+cygwin, *+clang.

Results of CI run: https://github.com/inkydragon/utf8proc/actions/runs/1324116342

[stevengj]

Thanks! It would be good to make it more similar to the Travis script (https://github.com/JuliaStrings/utf8proc/blob/master/.travis.yml), in that it should test the Makefile as well as cmake with both static and shared builds, make manifest, and make data

[inkydragon]

the Travis script

My understanding is that the .travis.yml mainly tests the usability of make. I will create a new make.yml to test make.

The part that tests cmake is already included in the new cmake.yml.

[inkydragon]

Now make.yml works. https://github.com/inkydragon/utf8proc/pull/2

Two changes are needed to enable MANIFEST testing on the mac

• brew install findutils or you got "find: -printf: unknown primary or operator"
• Add a new MANIFEST.mac because mac use .dylib instead of .so

  --- MANIFEST.new        2021-10-10 21:49:40.000000000 +0800
  +++ MANIFEST            2021-10-09 22:18:38.000000000 +0800
  @@ -1,9 +1,8 @@
  include/
  include/utf8proc.h
  lib/
  +lib/libutf8proc.2.dylib
  lib/libutf8proc.a
  -lib/libutf8proc.so -> libutf8proc.so.2.4.1
  -lib/libutf8proc.so.2 -> libutf8proc.so.2.4.1
  -lib/libutf8proc.so.2.4.1
  +lib/libutf8proc.dylib -> libutf8proc.2.dylib
  lib/pkgconfig/
  lib/pkgconfig/libutf8proc.pc