Use a method compatible with mongoid-observers to determinine the version of mongoid.

[dblock]

Fixes #121, see #123.

[coveralls]

Coverage increased (+0.07%) when pulling 7ab06f4 on dblock:fix-221 into 0c6aa47 on aq1018:master.

[dblock]

This build fails in rbx because of a gem dependent of versionomy, see dazuma/blockenspiel#13.

[johnnyshields]

👎 I don't think we need to introduce additional dependencies just to detect Mongoid version... can we use simple regex here?

[dblock]

I think we can't, because this is just a can of worms when we hit version 5.0pre or some other weird thing like that. The point of checking for a class was to make it 100% reliable. Except of course when something else defines that class ;)

[johnnyshields]

Mongoid::VERSION =~ /^3\./ will always match major version 3 (not 5.0.0pre, 13.x.x, etc)

[dblock]

@johnnyshields I am down with whatever change, or none :)

[zeitnot]

ping @dblock

[dblock]

Merged 8303884.

[zeitnot]

@dblock appreciated :)

[dblock]

I released 0.4.5.