Move ARMv8/gcc CI job from Travis to Azure

Add NO_AFFINITY to available CMAKE options on Linux, and set it to ON

* Mark iamax_sse.S as unsuitable for MIN due to issue #2116
* Use iamax.S rather than iamax_sse.S for ISMIN/ISAMIN on all x86_64 as workaround for #2116

to match the gmake default. Fixes second part of #2114

TST: Azure manylinux1 & clean-up

DOC: Add Azure CI status badge to README

Address redundant code concern #2113

* remove some of the steps & comments
from the original Azure yml template

* modify the trigger section to use
develop since OpenBLAS primarily uses
this branch; use the same batching
behavior as downstream projects NumPy/
SciPy

* remove Travis emulated ARMv6 gcc build
because this now happens in Azure

* use documented Ubuntu vmImage name for Azure
and add in a manylinux1 test run to the matrix

[skip appveyor]

using aytekinar's Alpine image and docker script from the Travis setup

[skip ci]

take out offending lines (although stolen from https://github.com/conda-forge/opencv-feedstock azure-pipelines fiie)

TST: add native POWER8 to CI

Change two http links to https

* add native POWER8 testing to
Travis CI matrix with ppc64le
os entry

[skip ci]

Fix errors in cpu affinity setup with glibc 2.6

Closes #2109

for #2114

Disable the SkyLakeX DGEMMIxCOPY kernels as well

#1955

as a stopgap measure for https://github.com/numpy/numpy/issues/13401 as mentioned in #1955

Misc. typo fixes in comments and documentation

sgemm/strmm kernel for power9