Docker container for sp_validation

[cailmdaley]

We could easily extend the shapepipe container into a new one that has all the additional sp_validation dependencies. I'm opening this issue to record packages/depedencies that are needed for sp_validation notebooks etc. but aren't listed as dependencies.

• pyccl
• TreeCorr (currently 4.3.3, need more recent version to write GGCorrelation covariance matrices)

On a related note, I noticed that when installing sp_validation in the shapepipe container, the versions of many packages changed which is not ideal for reproducibility. Maybe we can work towards making the version requirements between the two repositories consistent.