Ordered the lookup of machine IDs to guard against randomly ordered map key.
Merge pull request #259 from katco-/1329637-map-ordering

Ordered the lookup of machine IDs to guard against randomly ordered map ...

In Go v1.3, map ordering was intentionally randomized to discourage relying on maps which were coincidentally ordered how expected. This corrects a non-deterministic bug in one of the tests which was caused by this change to Go.