License Tag in Example not valid in current

[SteveGrehl]

According to the current XSD 'CC BY 4.0' is not a valid entry for the license tag.

See:

xlum_specification/xsd_schema/xlum_schema.xsd

Lines 219 to 231 in 84e766e

	<xs:attribute name="license" use="required">
	<xs:simpleType>
	<xs:restriction base="xs:string">
	<xs:enumeration value="CC BY"/>
	<xs:enumeration value="CC BY-SA"/>
	<xs:enumeration value="CC BY-NC"/>
	<xs:enumeration value="CC BY-NC-SA"/>
	<xs:enumeration value="CC BY-ND"/>
	<xs:enumeration value="CC BY-NC-ND"/>
	<xs:enumeration value="CC0"/>
	<xs:enumeration value="Copyright"/>
	</xs:restriction>
	</xs:simpleType>

It is however set in the provided example.

xlum_specification/examples/xlum_example.xlum

Lines 2 to 3 in 84e766e

	<xlum xmlns:xlum="http://xlum.r-luminescence.org" lang="en" formatVersion="1.0" flavour="generic" author="Marie Skłodowska-Curie; Max Karl Ernst Ludwig Planck"
	license="CC BY 4.0" doi="NA">

Hence it will produce errors such as the following

lxml.etree.XMLSyntaxError: Element 'xlum', attribute 'license': [facet 'enumeration'] The value 'CC BY 4.0' is not an element of the set {'CC BY', 'CC BY-SA', 'CC BY-NC', 'CC BY-NC-SA', 'CC BY-ND', 'CC BY-NC-ND', 'CC0', 'Copyright'}.

Either add the 'CC BY 4.0' to the license enumeration or adjust the example. Allowing a generic string as a license may be an option too.

[RLumSK]

@SteveGrehl Thanks!