fix(vagrant): enable patch-docker

This oneshot job needs to be run on every reboot.

Author: Matthew Fisher

contrib/coreos/user-data

@@ -6,7 +6,7 @@ coreos:
     peer-addr: 172.17.8.100:7001
   units:
   - name: docker-patch.service
-    command: start
+    command: enable
     content: |
       [Unit]
       Description=patch /usr/bin/docker with an S3 binary