Update version based on commit hash

[blrnw3]

instead of having the version hard coded (and updated when we do a new release) it would be great to have the version based on the current commit hash. Currently if you click the i button on the explorer it displays version but it would be really helpful if it showed the deployed version.

Version is hardcoded in server/init.py

[metakuni]

It would be extra nice if we could retrieve the deployed commit hash by hitting an endpoint similar to Portal's /deployed_version:

• https://api.cellxgene.cziscience.com/dp/v1/deployed_version

This would make it easier to verify deployments, especially while on-call.

[metakuni]

It might be good to include the commit hash from single-cell-infra as well. (e.g. for a quick way to check for config changes like https://github.com/chanzuckerberg/single-cell-infra/pull/442/files)

[atolopko-czi]

dup of newer issue #582