Quadratic Assignment from SciPy

[PaulWAyers]

We should probably look at quadratic assignment methods from SciPy as "back ends" for 2-sided permutation procrustes with one transformation. We have all that functionality (and more, I think) but we can at least use this as tests.

https://docs.scipy.org/doc/scipy/reference/generated/scipy.optimize.quadratic_assignment.html#scipy.optimize.quadratic_assignment

What do you think @FarnazH and @fwmeng88 ?

[FanwangM]

Thanks for noticing this.

This can be useful for 2-sided permutation Procrustes with one transformation. What is more interesting is the options argument which supports a lot of optimizers. So I think it's possible to add method="scipy" as the "back end" to add the support. The only thing I need to think more is how are we going to fit the options argument in scipy into our package.

@PaulWAyers @FarnazH