Add Go wrappers for MBA<2>

[yonch]

Thank you for open-sourcing this implementation! It had been a pleasure to work with on a Python project.

I wanted to use MBA<2> in Golang, so wrote these wrappers using cgo...

Verified using tests (in golang_mba_test.go):

• a port of the "small test function" test in test_mba.cpp
• generated several values using the interp Python example in the README, the Golang test then expects to generate the exact same values for the same inputs.

This implementation also support the functionality through Python's __repr__ via the String() function on the Mba2 struct.

I hope to continue contributing further fixes or enhancements in case those come up.

Thanks again for open sourcing!

[ddemidov]

Thank you for the contribution! Does it need any changes in the CMakeLists.txt to build the new test?

[yonch]

I test manually by running go test in the mba folder, but it will be good to add to the CMakeLists.txt if it's part of your workflow -- I'll go ahead and add that

[ddemidov]

Thanks again!

[yonch]

thank you for the quick turnaround!! hope to contribute more in the future :)

[ddemidov]

I have applied fixes for the go tests on travis-ci in 15cbf8de28de6a32f9b2f28568758032dd91d7a6 (the logs are here). Hope the fixes make sense.