Potion-client

Bugfixes
- Fixed `converters.schema_resolve_refs()` sometimes not resolving the correct root schema.

Bugfixes
- Fixed merge gone wrong.

Features
- Add `resource_cls` argument to `Client.resource_factory()` to allow specifying custom Resource classes
- Refactor `JSONSchemaDecoder` and add `schema_resolve_refs()` method for user-specified `{"$ref"}` resolution functions.

Bugfixes
- Fix reading Resource URI from "self" or "instances" links when possible.

Bugfixes
- Fixes installation issue in Python 2.7

This is a full rewrite of the Potion client.

If you have any feedback, feature requests or questions create an issue or write on Gitter.