Drop numpy 1.7 and 1.8 from tests and code - #6006

No change log needed? Shouldn't there be at least an entry that says Numpy 1.7 and 1.8 are no longer supported?

I think this gets done in the release notes, but you're right, might as well note it in the changelog, so we don't forget to add it!

Note that setup.py also needs to be required to enforce the minimum version of Numpy

Thanks! Also noticed circle is on 1.8, so that needs to change too. I updated things accordingly (I hope there is a 32-bit astropy docker image with 1.9...)

OK, my super-simple change for the docker image failed: how does one get a new one?

OK, all now passes except that for circleci we need a new docker image that has numpy >=1.9 installed. I have no idea how to go about that...

@astrofrog has the permission to upload a new docker image. What about creating one with a newer numpy that we could also use for v3.0dev? We also need a new one for the affiliated packages as the current one still runs np1.8 with astropy 1.2.1 (astropy/photutils#503 (comment))

Here is the repository where the docker image can be built:

https://github.com/astropy/astropy-docker/tree/master/32bit

It might be good for someone else to do this to make sure I am not a single point of failure (and I'm happy to add permissions to the docker hub for other people to upload).

Looking at the system requirements of docker, my laptop is at the edge of being supported (old os, with small RAM and hardly any free space). I could possibly borrow another one when needed, but it makes more sense for someone else stepping up for the task.

Sorry, don't have time to investigate things beyond what I can easily do in Debian.

@astrofrog I can update the docker image, but I need permissions.

EDIT: My docker hub username is lbradley.

@larrybradley - you should now have permissions

I uploaded a new docker image with numpy 1.12.1 (the latest release) and the CircleCI test passed. All is green now.

@astrofrog Can you give me permission to upload the new Dockerfile to astropy-docker? I didn't update the 32bit-with-astropy image (for affiliated packages). Should I do that too?

@larrybradley - thanks very much! Since I think there was general agreement on this change, in it goes!

@larrybradley - you now have permissions to upload the new Dockerfile to astropy-docker, can you do this? I have some other changes I need to make to the Dockerfile, and can regenerate the 32bit-with-astropy one once that's done.

@astrofrog Done, thanks!