Removed pin on sphinxcontrib-blockdiag

This broke local tox builds for me
on python3

added a tiny change to index.rst so that this
will trigger a verify

Issue-ID: CIMAN-33
Signed-off-by: Aric Gardner <agardner@linuxfoundation.org>
Change-Id: Iad3047f02c7e00f3aac1bb998e3750363479df1f
diff --git a/etc/requirements.txt b/etc/requirements.txt
index d75e59d..6f695d7 100644
--- a/etc/requirements.txt
+++ b/etc/requirements.txt
@@ -5,7 +5,7 @@
 setuptools
 six
 sphinx_rtd_theme>=0.4.3
-sphinxcontrib-blockdiag==1.5.5
+sphinxcontrib-blockdiag
 sphinxcontrib-needs>=0.2.3
 sphinxcontrib-nwdiag
 sphinxcontrib-seqdiag