Remove deprecated django.utils.importlib and replace with importlib

[alitinker]

django.utils.importlib was removed in 1.9. Replaced with importlib. Noticed issue #85 references an error related to this. I don't know if you're still accepting pull requests for this...

[garrypolley]

I'd be okay merging this change in, however, it means we no longer support Python 2.6, which I'm not against, but would be a major version increase.

https://docs.python.org/2.6/genindex-I.html <-- from reading that I don't think importlib is in Python 2.6, which we currenty support (or at least claim to support).

[dmarcelino]

@alitinker, @garrypolley, @gjain0 I'm also experiencing this, should we branch current master into 0.2 (for legacy purposes) and go for a new 0.3 version supporting django 1.9?

[garrypolley]

I'm fine if this gets merged.

[garrypolley]

I don't have time to test it at this moment, which is why I've not merged it yet.

[gauravvjn]

Can't we do something like below?

try:
    from django.utils.importlib import import_module
except ImportError: # for django >= 1.9
    from importlib import import_module

or if django.get_version() >= '1.9'

[garrypolley]

@gjain0 That works for me.

[garrypolley]

I like the import one the best.

[garrypolley]

Any care if I merge this?

It seems fine to me.