NNP test include refactoring [needs this in NNP repo] (#767)
NNP test include refactoring [needs this in NNP repo] (#767)

* move to test_nnp_backend.cpp

* format

* link libnnp.so in unittest

NervanaSystems/ngraph,NervanaSystems/ngraph,NervanaSystems/ngraph,NervanaSystems/ngraph