0.8.0: Towards production friendliness

[aeneasr]

This PR tackles various things.

Breaking Changes

• FindPoliciesForSubject was removed -> /policies no longer supports subject query parameter and instead offers pagination (offset (default 0), limit (default 500)) and is able to fetch all policies
• RethinkDB + Redis removed
• Upgrade ladon 0.5.0 -> 0.6.0 - requires database changes
• Go 1.8 required
• Move to ory namespace
• Log format is now JSON
• Policy for listing policies is now action=list, no longer action=find

Changes

• Move to ory/herodot
• Migrations need to be done by hand now
• Moved everything to one logger instance
• sql connections managable through DSN, introduced max_conns, max_idle_conns and max_conn_lifetime
• Introduce LOG_FORMAT which supports json and none (text) for now.
• swagger
• creating a JWK previously required keys alg and id. id got renamed to kid now.
• explain offline scope somewhere

To be done before merge

• Code review
• Test docker compose example extensively
• Apply migrations to an existing hydra database
• Test if policies work as expected in create scenarios

[aeneasr]

Ok, tests are now passing locally and all changes I wanted to address are now in. I'll give myself one or two days away from this issue and then review it and look for things that don't seem right.