Add CustomerAccount.customer_type reference, to MemberType

not 100% sure about the best naming here, hopefully this is good

corepos/db/office_op/model.py

@@ -801,6 +801,13 @@ class CustomerAccount(Base):
 
     customer_type_id = sa.Column('customerTypeID', sa.Integer(), nullable=True,
                                  default=1)
+    customer_type = orm.relationship(
+        MemberType,
+        primaryjoin=MemberType.id == customer_type_id,
+        foreign_keys=[customer_type_id],
+        doc="""
+        Reference to the :class:`MemberType` with which this account is associated.
+        """)
 
     charge_balance = sa.Column('chargeBalance', sa.Numeric(precision=10, scale=2), nullable=True,
                                default=0)