Setupification

* i realised my last pull request was on master, this is on andymckay as it should be
* added in `mkt up` command that updates the file only if it needs to

[setupification] marketplace-env $ bin/mkt up
Written fig file to /Users/andy/.mkt.fig.yml
Recreating andy_spartacus_1...

then

[setupification] marketplace-env $ bin/mkt up
Recreating andy_spartacus_1...
Thinking ahead this function name might get ambiguous in the future (e.g. we might have something that updates trees or updates b2d etc) - it should probably be a little closer tied to what it does.