Merge pull request #155 from gperdrizet/dev

Added lesson 19 activity notebook

Author: gperdrizet

notebooks/notebooks.yml

@@ -176,4 +176,11 @@ units:
           - name: "Activity"
             file: "Lesson_19_activity.ipynb"
           - name: "Activity solution"
-            file: "Lesson_19_activity_solution.ipynb"
+            file: "Lesson_19_activity_solution.ipynb"
+
+      - number: "20"
+        title: "Supervised learning classification"
+        topics: "Classification models: types, training, evaluation, regularization"
+        notebooks:
+          - name: "Activity"
+            file: "Lesson_20_activity.ipynb"