jenkins.sh: Build documentation as part of build verification

Change-Id: Iea7547c81fcd3e4268da23c18ad56d841aaf7535
diff --git a/contrib/jenkins.sh b/contrib/jenkins.sh
index e286047..efb913e 100755
--- a/contrib/jenkins.sh
+++ b/contrib/jenkins.sh
@@ -18,6 +18,11 @@
 # Execute automatically discovered unit tests first
 python -m unittest discover -v -s tests/
 
+# attempt to build documentation
+pip install sphinx
+pip install sphinxcontrib-napoleon
+(cd docs && make html)
+
+# run the test with physical cards
 cd pysim-testdata
 ../tests/pysim-test.sh
-