Added git submodule to Jenkinsfile

Jenkinsfile

@@ -7,7 +7,13 @@ node {
 }
 
   stage('Build') {
-    sh "'${mvnHome}/bin/mvn' -U clean verify -Ptextgrid.deb"
+    sh '''
+      echo "===>  Initialising submodules"
+      git submodule init
+
+      echo "===>  Compiling and building DEB package"
+      ${mvnHome}/bin/mvn -U clean verify -Ptextgrid.deb
+    '''
   }
 
   stage('Publish') {