add wording about removing files and folders in the output folder

Author: wing328

bin/java-petstore-retrofit.sh

@@ -28,6 +28,7 @@ fi
 export JAVA_OPTS="${JAVA_OPTS} -XX:MaxPermSize=256M -Xmx1024M -DloggerPath=conf/log4j.properties"
 ags="$@ generate -i modules/swagger-codegen/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml -l java -c bin/java-petstore-retrofit.json -o samples/client/petstore/java/retrofit  -DdateLibrary=joda,hideGenerationTimestamp=true"
 
+echo "Removing files and folders under samples/client/petstore/java/retrofit/src/main"
 rm -rf samples/client/petstore/java/retrofit/src/main
 find samples/client/petstore/java/retrofit -maxdepth 1 -type f ! -name "README.md" -exec rm {} +
 java $JAVA_OPTS -jar $executable $ags