setup the resources urls.

def setup_app(app, api):
    """setup the resources urls."""
    api.add_resource(
        KnwKBAllResource,
        '/api/knowledge'
    )
    api.add_resource(
        KnwKBResource,
        '/api/knowledge/<string:slug>'
    )
    api.add_resource(
        KnwKBMappingsResource,
        '/api/knowledge/<string:slug>/mappings'
    )
    api.add_resource(
        KnwKBMappingsToResource,
        '/api/knowledge/<string:slug>/mappings/to'
    )
    api.add_resource(
        KnwKBMappingsFromResource,
        '/api/knowledge/<string:slug>/mappings/from'
    )

    # for other urls, return "Method Not Allowed"
    api.add_resource(
        NotImplementedKnowledegeResource,
        '/api/knowledge/<string:slug>/<path:foo>'
    )