Merge pull request #2723 from alex/linkcheck-retry

Make the linkcheck builder more resillient against transient network …
diff --git a/docs/conf.py b/docs/conf.py
index dcc9c62..643eddb 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -273,3 +273,7 @@
 intersphinx_mapping = {'https://docs.python.org/3': None}
 
 epub_theme = 'epub'
+
+# Retry requests in the linkcheck builder so that we're resillient against
+# transient network errors.
+linkcheck_retries = 2