[Add] Template of unit tests for "AdaptiveRejectionMetropolisSampler" class.

The tests are just stub at this time.
[Add] Templates of unit tests for "MathNet.Numerics.Differentiation" classes.

Those are just stubs at this time.
[Add] C# wrapper class for "AdaptiveSamplingMetropolisSampling".

We are able to use ARMS from C# simply.