Add python daemon package as a cord-tester prerequisite

Change-Id: I14587417a5ac264c20ea237ec955c6dbe65fb8c3
diff --git a/src/test/setup/prerequisites.sh b/src/test/setup/prerequisites.sh
index bc3f4b2..13298e3 100755
--- a/src/test/setup/prerequisites.sh
+++ b/src/test/setup/prerequisites.sh
@@ -29,6 +29,7 @@
 pip install -U nsenter
 pip install -U pyroute2
 pip install -U netaddr
+pip install -U python-daemon
 pip install scapy-ssl_tls
 ( cd /tmp && git clone https://github.com/jpetazzo/pipework.git && cp -v pipework/pipework /usr/bin && rm -rf pipework )
 ## Special mode to pull cord-tester repo in case prereqs was installed by hand instead of repo