title: Adding resources with jwt_required?
body: <p>I've created an API using flask, where the authentication is all working fine using flask_jwt_extended. </p>
  
  <p>However if I add a resource that has a jwt_required decorator I get this error.</p>
  
  <pre><code>  File "/Library/Python/2.7/site-packages/flask_jwt/__init__.py", line 176, in decorator
      _jwt_required(realm or current_app.config['JWT_DEFAULT_REALM'])
  KeyError: 'JWT_DEFAULT_REALM'
  </code></pre>
  
  <p>Example resource:</p>
  
  <pre><code>class Endpoint(Resource):
  
      @jwt_required()
      def get(self):
          return {"State": "Success"}
  </code></pre>
  
  <p>Initialising the app:</p>
  
  <pre><code>app = Flask(__name__)
  api = Api(app)
  </code></pre>
  
  <p>Adding the resource:</p>
  
  <pre><code>api.add_resource(resource_class, "/myEndpoint")
  </code></pre>
  
  <p>The only way I can get it to work is to define the Endpoint class in the same file as the API. </p>
  
  <p>I think I need someway to pass the Realm into the endpoint class and have use the optional parameter on jwt_required to set the Realm. </p>