Add where_object query to PaperTrail::Version.

[JacobEvelyn]

I wasn't able to get this to work with native JSON types (an error will be raised when the query is attempted) due to not being able to accurately query for the full set of possible types (JSON's null, for instance). If anyone is able to give direction on how to make these queries work, please share!

I also wasn't sure if there's a better way to test this functionality; again, feedback welcome!

[batter]

@bradleypriest - Any tips for how to make these queries work with the Postgres JSON column type?

[batter]

@JacobEvelyn - Finally getting some time to go through this PR and try to figure out why Travis is failing. It seems like each DB adapter can have slightly different ways of outputting that SQL syntax depending on adapter and Ruby / Arel version, plus I'm thinking these aren't great tests anyways. We really want to test for whether the method can actually locate versions where the serialized object data has values in it matching what you pass in, so I'm going to try to refactor these tests to be something more along the lines of this and see if we can get these tests passing.

I also did some research on Postgres's JSON type and it seems that not all versions of Postgres support querying the JSON objects, so that one might be more tricky. We may have to leave that off for now.

[JacobEvelyn]

Thanks @batter. Let me know if I can be helpful. As I mentioned above, I wasn't sure what better way there was to test the functionality with the testing setup in place but I agree it's not really the right approach.

[JacobEvelyn]

😄

[panSarin]

It would be nice to add some documentation for that.

[batter]

Agreed. I'll see what we can do. Anyone is welcome to make a PR too.