Add libvncserver-dev package to unit-test build script

obmc-ikvm depends on libvncserver.

Change-Id: I7674f38fc790627e987f95786b49fbab6826cc06
Signed-off-by: Eddie James <eajames@us.ibm.com>
diff --git a/build-unit-test-docker.sh b/build-unit-test-docker.sh
index 85762f0..1032c6d 100755
--- a/build-unit-test-docker.sh
+++ b/build-unit-test-docker.sh
@@ -93,6 +93,7 @@
     libssl-dev \
     libevdev-dev \
     libevdev2-dbgsym \
+    libvncserver-dev \
     sudo \
     curl \
     git \