limit "no identity" test to a hardcoded dialect
limit "no identity" test to a hardcoded dialect

this test can't require "skip identity_columns" because
older Postgresql and Oracle report false for "identity_columns",
but their dialects won't skip actually rendering.

for now the only option is to hardcode to a non-identity
dialect.

Change-Id: Ia4f39f393b4ba10b3e82601a22ab75200cd52909

monetate/sqlalchemy,monetate/sqlalchemy,j5int/sqlalchemy,sqlalchemy/sqlalchemy,zzzeek/sqlalchemy,j5int/sqlalchemy