update gensim procrustes implementation

Hello,

The current gist (https://gist.github.com/louridas/a3cdb1b109ac03a8e202f4b19c9335b3) for the gensim Procrustes implementation does not work (due to changes in gensim).

I have made a fix here:

https://gist.github.com/louridas/a3cdb1b109ac03a8e202f4b19c9335b3

Best Regards,

Panos.