Retrieve growroot logs in the base job

This has already been added to base-test and appears to be working. Add
this to base so that the next time there are issues with growroot in
citycloud we have more data to debug with.

Change-Id: I813a2f9889607d050c0a69940e14853ff0fd4b35

playbooks/base/pre.yaml

@@ -13,6 +13,12 @@
     - name: Gather network facts
       setup:
         gather_subset: 'network'
+    # NOTE(clarkb) this is here to debug why some hosts don't seem to properly
+    # grow their root disks when jobs start.
+    - name: Check growroot logs
+      become: yes
+      ignore_errors: yes
+      command: journalctl -u growroot
 
   roles:
     - add-build-sshkey