Remove append original (#30)

* remove all traces of append_original

* remove all traces of append_original from UI

* add identity transformer

* update docs for removing append_original

* add error notifications when failing to refresh UI elements.

docs/walkthrough.rst

@@ -408,7 +408,7 @@ This should keep the Logistic Regression at its default values. If you'll notice
 
 .. admonition:: Appending original features to the meta-features
 
-   As of 0.4.0, Xcessiv no longer provides the checkbox option to append the original features to the meta-features. However, this functionality can be achieved by using the preset "Identity Transformer" and including this as a base learner in the ensemble. This approach reinforces the fact that a base learner is simply something that generates meta-features from features, and one that lets all features pass through unchanged fits this description.
+   As of 0.3.8, Xcessiv no longer provides the checkbox option to append the original features to the meta-features. However, this functionality can be achieved by using the preset "Identity Transformer" and including this as a base learner in the ensemble. This approach reinforces the fact that a base learner is simply something that generates meta-features from features, and one that lets all features pass through unchanged fits this description.
 
 
 After a short time, your ensemble should finish processing, and you'll be able to see its performance. Here we get an accuracy of 0.968, which is higher than any individual base learner.

xcessiv/ui/src/containers/ContainerBaseLearner.js

@@ -99,12 +99,22 @@ class ContainerBaseLearner extends Component {
   // Refresh base learner origins from server data
   refreshBaseLearnerOrigins(path) {
     fetch('/ensemble/base-learner-origins/?path=' + path)
+    .then(handleErrors)
     .then(response => response.json())
     .then(json => {
       console.log(json);
       this.setState({
         baseLearnerOrigins: json
       });
+    })
+    .catch(error => {
+      console.log(error.message);
+      console.log(error.errMessage);
+      this.props.addNotification({
+        title: error.message,
+        message: error.errMessage,
+        level: 'error'
+      });
     });
   }
 
@@ -525,6 +535,11 @@ class ContainerBaseLearner extends Component {
       console.log(error.message);
       console.log(error.errMessage);
       this.refreshingSE = false;
+      this.props.addNotification({
+        title: error.message,
+        message: error.errMessage,
+        level: 'error'
+      });
     });
   }