Edit/delete comments

Upgrade from 0.3:

1. Update config (database format changed to Knex)
2. node migrate0.3.0-0.4.0.js

• #19: Edit/delete own comments.
• Changing ORM again (using objection.js, but thinking about ditching that and only using knex).
• Using Bluebird for promises.
• Required node >= 4 - This is a microservice, does not need to be compatible with old
  interpreters!

I haven't really tested the Dynamic OpenID Connect authentication in this version.