Moped 2.0.0 / Mongoid 4.0.0 support

[pawelniewie]

No description provided.

[dblock]

There're a lot of failing specs.

I'd also want to make this work for both Mongoid3 and 4, which can be done using something similar to what's described in http://artsy.github.io/blog/2013/11/07/upgrading-to-mongoid4. If you make this work for v4 though I can do the latter part.

[dblock]

Note that I did fix the specs upstream.

Looks like Moped 2.0's node no longer has something called resolve_address, so the stub in the moped_session_helper is at least half of the problem.

[dblock]

Fixed via dblock@7228fb1, thanks for contributing - your code is mostly what it needed to be for Mongoid 4.

[pawelniewie]

Thanks for merging it in!