Add UniverSC to support other technologies

[TomKellyGenetics]

We've recently released an open-source tool to expand the functionality of Cell Ranger to apply to other technologies. We provide a Docker container on an open-source license (see #2) which can be used to run Cell Ranger on other technologies without violating the 10X Genomics EULA. Note that this only applies to scRNA-Seq techniques at this stage.

GitHub repo: https://github.com/minoda-lab/universc Docker container: https://hub.docker.com/r/tomkellygenetics/universc Manuscript: https://www.biorxiv.org/content/10.1101/2021.01.19.427209v1

I'm willing to prepare a PR to call UniverSC in place of Cell Ranger is there is interest in doing this.