Added dependency on websockify.

Eliminates the re-download of websockify on each launch of the container.

Dockerfile

@@ -8,6 +8,8 @@ ADD startup.sh /startup.sh
 RUN apt-get update -y && \
     apt-get install -y git x11vnc wget python python-numpy unzip Xvfb firefox openbox geany menu && \
     cd /root && git clone https://github.com/kanaka/noVNC.git && \
+    cd noVNC/utils && git clone https://github.com/kanaka/websockify websockify && \
+    cd /root && \
     chmod 0755 /startup.sh && \
     apt-get autoclean && \
     apt-get autoremove && \