code: def ro_rw_to_binds(ro, rw):
      
      out = {}
      if ro:
          for localdir, binddir in ro.iteritems():
              out[localdir] = {'bind': binddir, 'ro': True}
      if rw:
          for localdir, binddir in rw.iteritems():
              out[localdir] = {'bind': binddir, 'ro': False}
      return out
docs: ro and rw {localdir: binddir} dicts to docker-py's
      {localdir: {'bind': binddir, 'ro': T/F}} binds dicts