Bump version_info

This will allow Django to use DateTimeField with microseconds.
It checks the driver version here:
https://github.com/django/django/blob/master/django/db/backends/mysql/features.py#L53

pymysql/__init__.py

@@ -100,7 +100,7 @@ def get_client_info():  # for MySQLdb compatibility
 connect = Connection = Connect
 
 # we include a doctored version_info here for MySQLdb compatibility
-version_info = (1,2,2,"final",0)
+version_info = (1,2,6,"final",0)
 
 NULL = "NULL"