Make the doc build reproducible

This fixes Debian bug:
https://bugs.debian.org/826676

Change-Id: I638488448a4d6e644ab0e6deaebd65c92fa7904a

Author: thomasgoirand

doc/source/conf.py

@@ -80,7 +80,7 @@
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
-exclude_patterns = []
+exclude_patterns = ['**tests**']
 
 # The reST default role (used for this markup: `text`) to use for all
 # documents.