Merge pull request #918 from nonhermitian/extend_time_limit

Change cell timeout to 3 min

Author: nonhermitian

conf.py

@@ -73,7 +73,7 @@
 exclude_patterns = ['*.ipynb', '_build', 'legacy_tutorials',
                     '**.ipynb_checkpoints']
 
-nbsphinx_timeout = 120
+nbsphinx_timeout = 180
 nbsphinx_execute = 'always'
 nbsphinx_execute_arguments = [
     "--InlineBackend.figure_formats={'svg', 'pdf'}",