Type inconsistency when setting a connection's ingress/egress ports

[sajith]

Per set_ingress_port()'s docstring, the ingress_port argument is a Port. However, it is passed onto PortHandler.import_port_data() which seems to expect JSON.

datamodel/sdxdatamodel/models/connection.py

Lines 138 to 152 in 3a83c58

	#setter
	def set_ingress_port(self, ingress_port):
	"""Sets the ingress_port of this Connection.
	:param ingress_port: The ingress_port of this Connection. # noqa: E501
	:type: Port
	"""
	if ingress_port is None:
	raise ValueError("Invalid value for `ingress_port`, must not be `None`") # noqa: E501
	port_handler = PortHandler()
	self._ingress_port = port_handler.import_port_data(ingress_port)
	return self.ingress_port

It is similar for set_egress_port() too:

datamodel/sdxdatamodel/models/connection.py

Lines 165 to 178 in 3a83c58

	def set_egress_port(self, egress_port):
	"""Sets the egress_port of this Connection.
	:param egress_port: The egress_port of this Connection. # noqa: E501
	:type: Port
	"""
	if egress_port is None:
	raise ValueError("Invalid value for `egress_port`, must not be `None`") # noqa: E501
	port_handler = PortHandler()
	self._egress_port = port_handler.import_port_data(egress_port)
	return self.egress_port

Related to #61, probably.