Mongoid has removed options for Factory#build

Passing without_protected: true is no longer valid. Mongoid now
relies on ForbiddenAttributesProtection for this.

see: https://github.com/mongoid/mongoid/commit/33bd65d38754fb07aed533b0c0b15a31087fae87
mongo_session now checks for persistence options already

We don't need to clear persistence options.
See https://github.com/mongoid/mongoid/commit/af65a1bf78eb1b4d57904a843c628c09aadab0dd
Added test case for forcing document revision

Even if the document has not changed, revise! should
create a version
Ensure that existing mongo_session options are used for revisions

Also removed the monkey patch for collection as mongoid now picks up
the persistence options properly in the session.

Added the with scope when we search for revisions!
Merge pull request #1 from gautamrege/master

Added Tests for revise! and fixed a few errors