updating notebook with start of work for voronoi

Signed-off-by: Vanessa Sochat <vsochat@stanford.edu>

Author: vsoch

codeart/main.py

@@ -426,6 +426,10 @@ def add_file(self, filename, max_bytes=100000):
         """Based on a filename, add the filename to the appropriate code files
            instance depending on the extension. Ignore files in list of skip.
         """
+        # Must be readable / accessible
+        if not os.access(filename, os.R_OK):
+            return
+
         size = os.path.getsize(filename)
         name, ext = os.path.splitext(os.path.basename(filename))