Upgrade to opendpn3 v3

[mack0196]

Are there plans to update this simulator to opendnp3 v3.1.1?

[jadamcrain]

We don't plan to do so, but we would merge a PR that does so.

[mack0196]

Thanks for quick reply. If I make it work I'll submit a PR.

[jadamcrain]

Just FYI, this decision is mostly being made b/c we're pursuing a different DNP3 library:

https://stepfunc.io/blog/opendnp3-retrospective/

I think though that at some point we're interested in creating a test harness based on our new tech.