Workaround broken function in concourse scripts

See spring-io/concourse-java-scripts#11

Author: snicoll

ci/scripts/stage.sh

@@ -50,7 +50,7 @@ run_maven -f spring-boot-tests/spring-boot-deployment-tests/pom.xml clean instal
 git reset --hard HEAD^ > /dev/null
 if [[ $nextVersion != $snapshotVersion ]]; then
 	echo "Setting next development version (v$nextVersion)"
-	set_revision_to_pom "$nextVersion"
+	set_revision "$nextVersion"
 	git add pom.xml > /dev/null
 	git commit -m"Next development version (v$nextVersion)" > /dev/null
 fi;