Base: Ensure that AttributeAuthority requires 1 AttributeService.

Relating to issue #128 an AttributeAuthority could previously get
away with having no or no functioning AttributeService endpoints.

This resulted in invalid XML validation as follows:

    INFO  XmlSecTool - Reading XML document from file 'registry-tamaki-metadata-no-aa-endpoint.xml'
    INFO  XmlSecTool - XML document parsed and is well-formed.
    ERROR XmlSecTool - Invalid XML schema files, unable to validate XML
    org.xml.sax.SAXParseException: cvc-complex-type.2.4.a: Invalid content was found starting with element 'NameIDFormat'. One of '{"urn:oasis:names:tc:SAML:2.0:metadata":ContactPerson, "urn:oasis:names:tc:SAML:2.0:metadata":AttributeService}' is expected.
Metadata: Correct and extend classes with AA changes.

An AttributeAuthorityDescriptor is now correctly invalid if it is
missing at least 1 functioning AttributeService.

This commit corrects and extends test cases to properly check for
this change in Base.

References #128.
Merge pull request #128 from ausaccessfed/bugfix/#128-invalid-metadata-no-attribute-query-endpoint

FR generates invalid metadata with no AttributeQuery endpoint