Add clang format in for code format validation

The CI job will start validating code formatting when
.clang-format is found within the repo

Change-Id: I381cc2c07105e9f2cf33cadfab739681fd84b1e7
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
diff --git a/build-unit-test-docker.sh b/build-unit-test-docker.sh
index 1183d77..6031fac 100755
--- a/build-unit-test-docker.sh
+++ b/build-unit-test-docker.sh
@@ -66,7 +66,8 @@
     wget \
     git \
     dbus \
-    iputils-ping
+    iputils-ping \
+    clang-format-5.0
 
 RUN easy_install pip
 RUN pip install inflection