Merge pull request #354 from eric-wu/develop

backfill health code encryption GCM mode; fix dangling health code mappings for test users; refactor lock dao
Merge pull request #357 from eric-wu/develop

Fix Travis test failure
Merge pull request #358 from eric-wu/develop

Patch develop
Merge pull request #359 from eric-wu/develop

Patch develop
Merge pull request #361 from eric-wu/develop

One more patch for the develop stack
Merge pull request #363 from eric-wu/develop

Remove logging of encrypted id
Merge pull request #364 from eric-wu/develop

Fix Travis failure
Merge remote-tracking branch 'base/develop' into develop