[maven-release-plugin] prepare release trustyuri-1.21

Author: tkuhn

pom.xml

@@ -3,7 +3,7 @@
   <groupId>net.trustyuri</groupId>
   <artifactId>trustyuri</artifactId>
   <packaging>jar</packaging>
-  <version>1.21-SNAPSHOT</version>
+  <version>1.21</version>
   <name>trustyuri</name>
   <description>Trusty URI implementation for Java</description>
   <url>http://trustyuri.net</url>
@@ -106,7 +106,7 @@
     <url>https://github.com/trustyuri/trustyuri-java</url>
     <connection>scm:git:git@github.com:trustyuri/trustyuri-java.git</connection>
     <developerConnection>scm:git:git@github.com:trustyuri/trustyuri-java.git</developerConnection>
-    <tag>trustyuri-1.19</tag>
+    <tag>trustyuri-1.21</tag>
   </scm>
   <developers>
     <developer>