Bump the SciJava POM version

... so it uses the latest license-maven-plugin version.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

pom.xml

@@ -8,7 +8,7 @@
 	<parent>
 		<groupId>org.scijava</groupId>
 		<artifactId>pom-scijava</artifactId>
-		<version>1.27</version>
+		<version>1.28</version>
 	</parent>
 
 	<groupId>sc.fiji</groupId>