change db pattern

[mouadhkaabachi]

I think passing client_encoding=utf8 in create_postgresql_engine() directly no a good solution, client_encoding is for postgres, so if you use mysql or any thing else..., it won"t work

[hartym]

I am currently wondering if it's a good idea at all to have this "create_postgresql_engine" function in bbsqla. In fact, isn't it better to just use sqlalchemy.create_engine?

Having a specific PG option in a create_POSTGRESQL_engine function does not shock me, but I'm wondering if this is not a bit out of scope for the extension, what do you think?