[r=thumper],[bug=1231724] Make local provider work.
lp:1231724 shows that if a local provider is bootstrapped,
the created directory $(JUJU_HOME)/environments is not readable
by the user that started the provider as the bootstrap is done
by root, and the files and directories created are owned by
root with 0600 permission, which means you can't even run
juju status on a bootstrapped local provider.
https://codereview.appspot.com/14258043/