Launch dbus session for docker unit tests

Fix for openbmc/openbmc#1137

Change-Id: I9e8a41820c6b85bff3625af4ab7b488a66b39c65
Signed-off-by: Leonel Gonzalez <lgonzalez@us.ibm.com>
diff --git a/build-unit-test-docker.sh b/build-unit-test-docker.sh
index cc1d887..61b5430 100755
--- a/build-unit-test-docker.sh
+++ b/build-unit-test-docker.sh
@@ -63,7 +63,8 @@
     libssl-dev \
     sudo \
     wget \
-    git
+    git \
+    dbus
 
 RUN easy_install pip
 RUN pip install inflection