JSON question mark operators don't work

[Vlix]

When trying to use the new (since PostgreSQL 9.4) operators on jsonb that contain question marks, the package incorrectly assumes they are parameters to be replaced with values by Database.PostgreSQL.Simple.buildQuery.

I propose a change to buildQuery that escapes ?? to ? without trying to count it as a to be replaced parameter. This is a very common method of escaping question marks in prepared statements afaik.
I also don't expect anything breaking after this change, but if anyone knows of an instance this change may break something, do tell.

I can make a pull request if desired.

[Vlix]

I've made the pull request and updated it to include tests for the new jsonb operators