WIP: Motif search

[mkonstanty]

This feature adds possibility to search for a MOTIF using Prody package.

[jamesmkrieger]

Thanks for adding this new functionality. It sounds good. I still need to look through it properly though.

In the meantime, if you could reverse all the unrelated formatting changes, that would be make it much easier to follow. Thanks

[jamesmkrieger]

Everything look much better now. Thanks.

Still if you could replace f strings with older types of formatting, that would be great. We need compatibility with python 2.7 for building the prody website.