DeprecationWarning importing past.translation in Python 3.7

[tmnilsson]

I'm getting the following warning when importing past.translation:

past/translation/init.py:35: DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses
import imp

Would it be possible to change from imp to importlib?

[danyeaw]

I took a look at this as part of #421. This change will require someone to do some digging and comparison between imp and importlib and maintain backwards compatibility with Python 2 as well, it isn't a 1:1 replacement where you can just import importlib instead of imp.