metadata doesn't serialize naming convention #3362
Description
Migrated issue, originally created by Michael Bayer (@zzzeek)
from sqlalchemy import Table, Column, MetaData, Integer
import pickle
m = MetaData(naming_convention={"pk": "%(table_name)s_pk"})
t = Table('t', m, Column('id', Integer, primary_key=True))
m2 = pickle.loads(pickle.dumps(m))
t2a = Table('t2', m, Column('id', Integer, primary_key=True))
t2b = Table('t2', m2, Column('id', Integer, primary_key=True))
assert t2a.primary_key.name == t2b.primary_key.name