Clean up some details in tutorial notebooks

Author: mwcraig

docs/source/examples/Using Interact.ipynb

@@ -392,7 +392,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "The widget is a `Box`, which is a container for other widgets."
+    "The widget is an `interactive`, a subclass of `VBox`, which is a container for other widgets."
    ]
   },
   {
@@ -408,7 +408,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "The children of the `Box` are two integer-valued sliders produced by the widget abbreviations above."
+    "The children of the `interactive` are two integer-valued sliders and an output widget, produced by the widget abbreviations above."
    ]
   },
   {
@@ -629,7 +629,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.5.2"
+   "version": "3.6.1"
   },
   "widgets": {
    "application/vnd.jupyter.widget-state+json": {