Mimesis: Add support of custom providers.

[lk-geimfari]

We need to realize something like this:

>>> from elizabeth import Generic

>>> generic = Generic('en')

>>> class SomeProvider():
        def hello(self):
            return "Hello!"

>>> class Another():
        def bye(self):
            return "Bye!"

>>> generic.add_provider(SomeProvider)
>>> generic.add_provider(Another)

>>> generic.someprovider.hello()
>>> generic.another.bye()
# Hello!
# Bye!

[lk-geimfari]

@Battleroid What do you think about it? Do you have interest? If you can help me with this I could take the documentation update.

[Battleroid]

Sounds neat. Is there anything in particular you would like me to do? I'll try to get started on it in the morning.

[lk-geimfari]

@Battleroid We need just add_provider() method. It would be great if you can do it. Thank you very much!

[Battleroid]

Created PR #76, hopefully this is what you're looking for.

[lk-geimfari]

@Battleroid Thank you!

[Battleroid]

To be honest it's whatever you prefer. I think either way is good, the former might be preferable since you are just calling the class just as you would normally. The latter might be a little bit more odd since you're changing the case.

If need be though you could probably have add_provider name the new provider before setting it as an attribute by looking for a variable within the provider class, then defaulting to the class name if it's not available.

e.g. SampleProvider might have a subclass named Meta which contains our name.

class SampleProvider:
    ...

    class Meta:
        name = 'sampleprovider'

And we'd use Meta.name to label it, or even simpler,

class SampleProvider:
    name = 'sampleprovider'

    ...

[lk-geimfari]

@Battleroid Variant with Meta is also great! Thank you!

[Battleroid]

Created PR #77 for the Meta class variant.

[lk-geimfari]

@Battleroid It's great! Thanks.

[Battleroid]

No problem, glad it works.