Add pysnmp module to build-qemu-robot-docker.sh

Need this package and other packages listed in
build-qemu-robot-docker.sh to run a script which
power cycle's a system via PDU's SNMP interface.

Change-Id: If34ec35065ab988f68c2bbe1fd9b531edc083005
Signed-off-by: Sunil M <sunilmam@us.ibm.com>
diff --git a/scripts/build-qemu-robot-docker.sh b/scripts/build-qemu-robot-docker.sh
index 58b6fb0..8eb2cc9 100755
--- a/scripts/build-qemu-robot-docker.sh
+++ b/scripts/build-qemu-robot-docker.sh
@@ -65,7 +65,8 @@
     robotframework \
     robotframework-requests \
     robotframework-sshlibrary \
-    robotframework-scplibrary
+    robotframework-scplibrary \
+    pysnmp
 
 RUN wget https://sourceforge.net/projects/ipmitool/files/ipmitool/1.8.18/ipmitool-1.8.18.tar.bz2
 RUN tar xvfj ipmitool-*.tar.bz2