* Add missing files + import paths for libddoc/common to build.bat
* Add Github Actions setup to replace Travis
The configured workflow tests D-Scanner with different host compilers
(DMD / LDC / GDC) on different platforms ( Windows / OSX / Linux).
The tests include
- `build.bat test` (windows) or `make test`
- `dub test` for version ranges of `libdparse` and `dsymbol`
(currently disabled because of unresolvable dependency constraints)
- `make lint`
- phobos linting
WebFreak001
Florian