Add jgitver extension

.mvn/extensions.xml

+<extensions xmlns="http://maven.apache.org/EXTENSIONS/1.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/EXTENSIONS/1.0.0 http://maven.apache.org/xsd/core-extensions-1.0.0.xsd">
+  <extension>
+    <groupId>fr.brouillard.oss</groupId>
+    <artifactId>jgitver-maven-plugin</artifactId>
+    <version>1.7.1</version>
+  </extension>
+</extensions>