project.json should be dumped with a trailing newline

[phorward]

Occasionally, when editing settings in project.json, this happens:

--- a/project.json
+++ b/project.json
@@ -34,4 +34,4 @@
         "application_name": "myapp-viur3",
         "version": "$(year)-$(month)-$(day)-$(user)"
     }
-}
\ No newline at end of file
+}

A solution for this would be to simply append an \n each time the file is being stored by viur-cli.