Add kernelspec tool

tools/fix_kernelspec.py

@@ -0,0 +1,19 @@
+import os
+
+import nbformat
+
+from generate_contents import iter_notebooks, NOTEBOOK_DIR
+
+def fix_kernelspec():
+    for nb_name in iter_notebooks():
+        nb_file = os.path.join(NOTEBOOK_DIR, nb_name)
+        nb = nbformat.read(nb_file, as_version=4)
+
+        print("- Updating kernelspec for {0}".format(nb_name))
+        nb['metadata']['kernelspec']['display_name'] = 'Python 3'
+
+        nbformat.write(nb, nb_file)
+
+
+if __name__ == '__main__':
+    fix_kernelspec()