Outdated xarray on staging env

[jbusecke]

The staging environment is now already two xarray versions behind (v0.17.0 vs v0.19.0 released). This was causing a bunch of issues for users who want to utilize the new xarray functionality (e.g. jbusecke/xMIP#172), which can be solved by manually installing the new version on the notebook and workers.

But given the importance of xarray to the community, could we trigger a rebuild that includes the newest xarray version?

[rabernat]

The image itself is configured in https://github.com/pangeo-data/pangeo-docker-images.

The latest pangeo-notebook version (00bb342) has xarray 0.18.2: https://github.com/pangeo-data/pangeo-docker-images/blob/master/pangeo-notebook/conda-linux-64.lock#L426

AFAIK, an update should be possible by updating the tag here:
https://github.com/pangeo-data/pangeo-cloud-federation/blob/staging/deployments/gcp-uscentral1b/image/binder/Dockerfile#L1

to

FROM pangeo/pangeo-notebook:00bb342