Incorrect warning "Warning: matrix is not full rank"

[Nanne]

In steer2HarmMtx.py numpy.rank() is used to get the matrix rank. However, this function is deprecated and replaced by the .ndim attribute, because numpy.rank() did not return the matrix rank, but the number of dimensions.

Instead the numpy.linalg.matrix_rank() should be used to obtain the matrix rank.

The same also goes for the use of numpy.rank() in pyPyrUtils.py