Pin opendp version number

https://github.com/dpella/webdp-v2/blob/e25325c1810fca823959761751db6274e570011a/Engines/opendp/Dockerfile#L9

I'd suggest that you pin the version number for opendp in the Dockerfile. We should have a new 0.10 release out in the next few weeks: While we are on 0.x versions we aren't guaranteeing perfect backward compatibility.

The project looks interesting!