Set up continuous integration for C++ and C#

[rwmcintosh]

Windows and Linux

[PavelBal]

1. Build windows C++/C# libs
2. Build linux libs
3. Build R package
4. Build website

[Felixmil]

Superseded by #122 ?

[PavelBal]

One step at a time, we are not sure how to set up CI for C++/C# libs. First, lets have this running for R.

[PavelBal]

@Felixmil @Yuri05

Right now we build the C++/C# libs locally, commit the updated DLLs, and the CI (GitHub actions) only builds the R package. Is it possible to do C++/C# building also with GA?

[PavelBal]

Related: #121

[Felixmil]

I'm sure it is possible (cf https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-net) but I have no experience in building C++/C#. Though, I have enough experience to provide support for translating technical requirement (provided by Rob) to github actions/workflow.

[rwmcintosh]

It's probably no problem for the .NET assemblies, but the native dll's are a different story. We need to produce a package containing rSharpUx.so and rSharpMs.dll for Ubuntu and Windows respectively. You need both OS's to build them.