Add a dummy lsb_release command to test binaries

This should allow us to run tests on os x using the current dokku binary

tests/bin/lsb_release

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+if [[ "$(uname)" == "Darwin" ]]; then
+  echo "Darwin"
+else
+  echo "Ubuntu"
+fi