Remove version file
Update gem development dependencies
Move embedded file into model directory.
Add pagination errors
Add ResultSet class.

It is an enumerable and iterates over the objects.
Return a ResultSet on `find` and `all` methods
Update documentation
Add a message for the exception
Update README with pagination examples.
Install last Riak DB to fix Travis. This is a temporal fix.

Travis uses riak 1.2.x and pagination needs 1.4.x.
Merge pull request #15 from emancu/8-support_pagination

Support pagination