sorting imports on save; cleanup imports sorting; add isort check (#207)

notebooks/notebook_imports.py

@@ -2,12 +2,12 @@
 import imageio
 import mediapy as media
 
-# ipython stuff
-from IPython import get_ipython
-
 # plotly stuff
 import plotly.graph_objects as go
 
+# ipython stuff
+from IPython import get_ipython
+
 
 def setup_ipynb():
     """