Code review comment for lp:~cjwatson/charms/trusty/turnip/build-label

Just a minor formatting issue.

I'm working through updating Rutabaga's charm similarly as a somewhat circumlocuitous form of review. No doubt fine, given the mojo spec ran, but thought it might be worth leaving this open in the event that I came across anything in the process.

Given our services will be duplicating a reasonable amount of charm code, I did wonder if we should consider maintaining our own charmhelpers like library.