Develop PHDC address builder

[m-goggins]

The addr section is not required for building the patientRole section within the recordTarget of a PHDC case report, but it is information we are likely to have and want included. We are also likely to encounter and need to populate other addresses, e.g., hospital address. This generic addr helper function should be able to populate with data from the message parser.

Acceptance Criteria:
A helper method called _build_addr is added to the PHDCBuilder class. The method uses lxml to build out the following elements:

			<addr use="">
				<streetAddressLine>14 WILLOW GLEN Apt. 2</streetAddressLine>
				<city>SANDY SPRINGS</city>
				<state>13</state>
				<postalCode>30029</postalCode>
				<county>Fulton</county>
				<country>840</country>
			</addr>
			

For context, address will nest in patientRole like so:

<recordTarget>
		<patientRole>
			<id extension="" root="" assigningAuthorityName=""/>
			<addr use="">
				<streetAddressLine>14 WILLOW GLEN Apt. 2</streetAddressLine>
				<city>SANDY SPRINGS</city>
				<state>13</state>
				<postalCode>30029</postalCode>
				<county>Fulton</county>
				<country>840</country>
			</addr>
			<telecom use="" value=""/>
			<patient>
				<name use="">
					<prefix>Mr.</prefix>
					<given>Surma</given>
					<given>J</given>
					<family>Singh</family>
				</name>
				<administrativeGenderCode code="M" displayName="Male" codeSystem="2.16.840.1.113883.12.1" codeSystemName="Administrative sex (HL7)"/>
				<birthTime value="19900101"/>
				<sdtc:raceCode code="2106-3" displayName="White" codeSystem="2.16.840.1.113883.6.238" codeSystemName="Race &amp; Ethnicity"/>
				<ethnicGroupCode code="2186-5" displayName="Not Hispanic or Latino" codeSystem="2.16.840.1.113883.12.1" codeSystemName="Administrative sex (HL7)"/>
			</patient>
		</patientRole>
	</recordTarget>