Revert "Block non-mysqldb / pymysql from testing Enum"
Revert "Block non-mysqldb / pymysql from testing Enum"

This reverts commit 55843040b1b4e1493e27051f5125fa322a43dc31.

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