Switching to the 'develop' branch is relatively straight-forward using
one of the entries in the list here:
There doesn't seem to be an obvious option to switch back to 'master'
though following the advice on the dev list since 'develop' is
undergoing a lot of work at the moment.
I thought '0-latest' might work, which maps to ' mynewt_0_9_0_tag' but
that is > 600 commits behind master:
Should a new entry be adding pointing directly to the 'master' branch or
am I perhaps missing something obvious here?