Added badges for TravisCI and Coveralls to the README
Coveralls: We're using travis-ci not travis-pro
Replaced bcrypt with SHA-512
Made Groups API REST available on global admin router
Added authz tests for getting/updating group members on the global admin
Tweak documentation for hashing/comparing passwords
Merge branch 'bcrypt-to-sha512'

* bcrypt-to-sha512:
  Tweak documentation for hashing/comparing passwords
  Replaced bcrypt with SHA-512
Fixed bad REST documentation in groups
Subscribing and unsubscribing from series
Serie subscriptions

* A user id can be specified when (un)subscribing
* Refactored DAO.getOrgUnits method signature slightly
* Expanded unit tests
* Cleaned up jsdocs