[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.
inkydragon#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