Swap Transformations

[shachardon]

Thank you for your great work! It's super useful!

I have a suggestion for improvement -
Some transformations are working with a "swap" principle. For example, in GenderSwap, if we had "sister" in the original sentence then it would be transformed to 'brother" and vice versa.
There are scenarios when it's important to know what direction the transformation went, female to male or male to female. In my case for example, I want to compare the performances of my model on female/male sentences on inference time.

I really liked the way TenseTransformation works. You need to specify in the constructor what tense (past/present/future) you want to transform to.
Maybe that could be applicable for other swap transformations?

Thanks again!