test both memory and file-based
- When selecting from a UNION using an attached database file,
the pysqlite driver reports column names in cursor.description
as 'dbname.tablename.colname', instead of 'tablename.colname' as
it normally does for a UNION (note that it's supposed to just be
'colname' for both, but we work around it).  The column translation
logic here has been adjusted to retrieve the rightmost token, rather
than the second token, so it works in both cases.   Workaround
courtesy Tony Roberts.
fixes #3211

:meth:`.Inspector.get_temp_view_names`; currently, only the
SQLite dialect supports these methods.    The return of temporary
table and view names has been **removed** from SQLite's version
of :meth:`.Inspector.get_table_names` and
:meth:`.Inspector.get_view_names`; other database backends cannot
support this information (such as MySQL), and the scope of operation
is different in that the tables can be local to a session and
typically aren't supported in remote schemas.
fixes #3204

The sqlite get_unique_constraints() implementation did not do a union
against the sqlite_temp_master table like other code does. This could
result in an exception being raised if get_unique_constraints() was
called against a temporary table.

sqlalchemy/orm, sqlalchemy/event, sqlalchemy/testing

to get all flake8 passing

fixes #3110