Assuming the next 0.21 release happens around or after April 2019, the oldest Ubuntu LTS at that point will be 16.04 LTS, which includes,

• numpy 1.11.0
• scipy 0.17.0

(checked in a Docker image, not sure where to find the official information)

so we could probably make these our minimum requirements for 0.21.

Making so would for instance allow to implement #11638

Even assuming there is agreement on this subject, we should probably wait for 0.20.1, at least, before doing anything about it. Eventually this would involve,

• adjusting versions of dependencies in docs and CI
• removing the utils.fixes that are no longer needed.