Added the ability to set a database per Model (branch v2.0.0)

[Flambe]

We use multiple databases in our Mongo set up. This pull request allows the database to be set on a per model basis. If no database is set, it falls back to the default as to not break backwards compatibility.

Requires PR60 from mongolid

[gmsantos]

Hi @Flambe, could you rebase your PR to master branch?

We going to release 2.0 soon but before that we need to organize some things, like dropping old branches.

[coveralls]

Coverage decreased (-1.8%) to 96.429% when pulling 58a2d4e4ee0fd92aa88118b94b95ee33f16b8161 on Flambe:v2.0.0 into 5174633c8ace5fe39bdaed229f870f0c79ffee25 on leroy-merlin-br:v2.0.0.

[Flambe]

@gmsantos Should be good now. StyleCI is failing on docs I haven't touched, but I can fix if you want me too. Or not, I need more practice with rebasing.

[coveralls]

Coverage decreased (-1.8%) to 96.429% when pulling d9df56886f70a7f9580f398dc1e981f9ba1a7b99 on Flambe:v2.0.0 into 5174633c8ace5fe39bdaed229f870f0c79ffee25 on leroy-merlin-br:v2.0.0.

[coveralls]

Coverage decreased (-1.8%) to 96.429% when pulling ceab18440ccc7fca5af3b75ea8f2f65772ec92f7 on Flambe:v2.0.0 into 5174633c8ace5fe39bdaed229f870f0c79ffee25 on leroy-merlin-br:v2.0.0.

[gmsantos]

@Flambe dont worry, we can squash before merge :D

[gmsantos]

note: how mongo authentication are handled in that case

[diegofelix]

It's hard to test this feature, for example, how do we handle database authentications per models? @Flambe Do you still want this feature, or I can close the PR?

[Flambe]

@diegofelix It's not needed by me any more, feel free to close it!