[UT] moved unit tests for Phi and invPhi to Sigmoid tests
[UT] moved unit tests for Phi and invPhi to Sigmoid tests

esc/Psignifit-3.x,esc/Psignifit-3.x,esc/Psignifit-3.x,esc/Psignifit-3.x,esc/Psignifit-3.x,esc/Psignifit-3.x