Askari::Schema.from_resource loads a schema as a java resource.

Since it isn't very easy or meaningful to mock the relevant java
facilities, the spec has become an integration spec & uses
`spec/example_app/config/askari.yml`.
Merge pull request #53 from seomoz/phs/load-schema-as-resource

Askari::Schema.from_resource loads a schema as a java resource.