build-unit-test-docker: Add extra test tools

 - lcov: Used for producing coverage results
 - valgrind: Used for memleak and thread sanity checking

Change-Id: I8f0359f7214e4aa0bc4e22fa3bec8f63c86cd040
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/build-unit-test-docker.sh b/build-unit-test-docker.sh
index d510273..63bacbc 100755
--- a/build-unit-test-docker.sh
+++ b/build-unit-test-docker.sh
@@ -84,7 +84,9 @@
     libnl-3-dev \
     libnl-genl-3-dev \
     libconfig++-dev \
-    libsnmp-dev
+    libsnmp-dev \
+    valgrind \
+    lcov
 
 RUN pip install inflection
 RUN pip install pycodestyle