fixup readme, add manylinux1 wheels

[mattip]

PR gh-78 was merged, we now have manylinux2010 wheels on anaconda.org. I thought we could convert manylinux2010 to manylinux1, but that was not correct. If we want manylinux1 wheels, we must add azure jobs to do so

This PR adds 6 more jobs to build manylinux1 for python3.6, 3.7, 3.8; 32 and 64 bit. It also fixes the README for the new wheel locations.

[mattip]

closes gh-77

[mattip]

The uploads are failing since this is a PR from my branch. Once numpy/numpy#16055 goes in I can change the build tag to the appropriate commit (right now it is c24acd7) and the 32-bit linux builds should succeed.

[charris]

Let's just merge this and see how it goes. Thanks Matti.

[mattip]

I disabled the first appveyor webhooks (search for Active on the webhook page) without deleting, so if we wish we can re-activate them. Should I remove the file I added in #78?

[charris]

Hmm, looks like we need a link to the azure pipelines up top of the README. Looks like https://dev.azure.com/numpy/numpy/_build?definitionId=8&_a=summary&view=runs is as good as any.

[charris]

I disabled the first appveyor webhooks

I noticed that :) Yes I think we can rename the files again. I'll need to reenable for 1.18.4, which still has Python3.5, but will disable after that release is built. There were 3 appveyor hooks, I deleted one and was just re-enabling them separately to see which of the remaining two we could also delete.

[charris]

Do you still think we need to move wheel builds to numpy? Seems that it should be pretty easy as long as we are just using azure builds.

[charris]

Looks like 32 bits is still failing. I assume it is because we need to point to the top of the branch with the tools update instead of 'v1.18.3'. Might be good if any builds triggered in the master branch went into the nightly folder.

[mattip]

The 32-bit failures have to do with avx loops and the -msse2 flag which was missing on the appveyor/travis builds, see the comment in gh-74. I will remove it and see if that helps.

Might be good if any builds triggered in the master branch went into the nightly folder

This was triggered off the HEAD of maintenance/1.18.x, and the files were uploaded as https://anaconda.org/numpy-1.18.4.dev0+f1be9e5-*. I will make that explicit.