Integrate lcov tool for generating unit test code coverage report.
Bump git version to latest.

Change-Id: Ifc2f19edad0309cc102c415d7ab75f349f2582ad
diff --git a/docker/Dockerfile.openolt-test b/docker/Dockerfile.openolt-test
index e25f918..1326df8 100644
--- a/docker/Dockerfile.openolt-test
+++ b/docker/Dockerfile.openolt-test
@@ -16,7 +16,7 @@
 
 # Update to have latest images
 RUN apt-get update && apt-get -q -y install \
-    git=1:2.7.4-0ubuntu1.7 \
+    git=1:2.7.4-0ubuntu1.9 \
     pkg-config=0.29.1-0ubuntu1 \
     build-essential=12.1ubuntu2 \
     autoconf=2.69-9 libtool=2.4.6-0.1 \
@@ -34,7 +34,8 @@
     ccache=3.2.4-1 \
     g++-4.9=4.9.3-13ubuntu2 \
     wget=1.17.1-1ubuntu1.5 \
-    ca-certificates=20170717~16.04.2 && \
+    ca-certificates=20170717~16.04.2 \
+    lcov=1.12-2 && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/*