Add pyproject.toml file to replace setup_requires

5 jobs for master in 32 minutes and 16 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #7519
check-setup

00:02:00

passed #7520
docs

00:04:37

passed #7516
py35

00:05:41

75.0%
passed #7517
py36

00:05:31

75.0%
passed #7518
py37

00:14:25

75.0%