Update packages and utilize error classes from rest-facade correctly (Fixes #154)

[charsleysa]

Fixes #154

• Use error classes from rest-facade for consistency
• Fix APIError not being constructed correctly by rest-facade due to missing errorFormatter config
• Fix test case in oauth.tests.js incorrectly using return twice

[coveralls]

Coverage increased (+0.3%) to 95.567% when pulling c7b531c on charsleysa:master into ba4b4f9 on auth0:master.

[coveralls]

Coverage increased (+0.3%) to 95.524% when pulling e5e9405 on charsleysa:master into cdcf916 on auth0:master.