Added sshpass to docker image

The sshpass command is needed for programs that wish to ssh from a shell
command line.  When running from a program, it is undesirable to be
prompted for a password.

Change-Id: Ibb303576e717b1989f5d58b6e2b7cf8d13655c7c
Signed-off-by: Michael Walsh <micwalsh@us.ibm.com>
diff --git a/scripts/build-qemu-robot-docker.sh b/scripts/build-qemu-robot-docker.sh
index 8eb2cc9..a4747bd 100755
--- a/scripts/build-qemu-robot-docker.sh
+++ b/scripts/build-qemu-robot-docker.sh
@@ -53,7 +53,8 @@
     curl \
     build-essential \
     libpixman-1-0 \
-    libglib2.0-0
+    libglib2.0-0 \
+    sshpass
 
 RUN easy_install \
     tox \