Change license from CC0 to Unlicense

The latter is arguably more appropriate for source code.

Author: ctrueden

pom.xml

@@ -17,8 +17,8 @@
 	</organization>
 	<licenses>
 		<license>
-			<name>CC0 1.0 Universal License</name>
-			<url>https://creativecommons.org/publicdomain/zero/1.0/</url>
+			<name>Unlicense</name>
+			<url>https://unlicense.org/</url>
 			<distribution>repo</distribution>
 		</license>
 	</licenses>