Add opsclass to exclusion constraint
Added new parameter :paramref:`_postgresql.ExcludeConstraint.ops` to the
:class:`_postgresql.ExcludeConstraint` object, to support operator class
specification with this constraint. Pull request courtesy Alon Menczer.
Fixes: #5604
Closes: #5700
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5700
Pull-request-sha:
f8613e100792fc0bb3cf300ec6aebc78ecdf0361
Change-Id: Iaf664131ec84f8c2fb05edf799198b8d3bb83597
(cherry picked from commit
018aa9870110ef97316e9984c7ecd7f3357b501a)