openvpn.sh: Add wrapper script

* Add the beginning of a wrapper script that will handle cert generation
  and OpenVPN invocation.

Dockerfile

@@ -5,7 +5,12 @@ FROM ubuntu:14.04
 MAINTAINER Kyle Manna <kyle@kylemanna.com>
 
 RUN apt-get install -y openvpn iptables curl
+
 ADD ./bin /usr/local/sbin
+RUN chmod a+x /usr/local/sbin/*
+
 VOLUME /etc/openvpn
+
 EXPOSE 443/tcp 1194/udp 8080/tcp
-CMD run
+
+ENTRYPOINT ["openvpn.sh"]