[maven-release-plugin] prepare release v3.1

Author: yagee-de

pom.xml

@@ -8,14 +8,14 @@
   </parent>
   <groupId>org.mycore.iview2</groupId>
   <artifactId>image-tiler</artifactId>
-  <version>3.1-SNAPSHOT</version>
+  <version>3.1</version>
   <name>MyCoRe IView2 Image Tiler Library</name>
   <description>Image Tiling Library</description>
   <scm>
     <connection>scm:git:https://github.com/MyCoRe-Org/image-tiler.git</connection>
     <developerConnection>scm:git:https://github.com/MyCoRe-Org/image-tiler.git</developerConnection>
     <url>https://github.com/MyCoRe-Org/image-tiler/tree/master</url>
-    <tag>HEAD</tag>
+    <tag>v3.1</tag>
   </scm>
   <properties>
     <java.target.version>11</java.target.version>