Add sphinx-reload to requirements.txt

Change-Id: Ib318e761008ebe6f3cf146c323417263104a7155
diff --git a/requirements.txt b/requirements.txt
index e81d18d..c3ae0c0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,3 +5,4 @@
 sphinx-rtd-theme~=0.5.2
 sphinxcontrib-spelling~=7.2.1
 sphinx-multiversion~=0.2.4
+sphinx-reload~=0.2.0