On pypy3 on Travis (version 5.8.0), running with coverage
enabled causes significant slowdown and test_build_meta
ends up timing out or otherwise failing. Until that is
fixed, skip coverage on pypy3 on Travis.

Some of these environment variables are necessary codecov to
detect that it is on travis/appveyor and thus doesn't need
an upload token.

Stop patching write_pkg_info

Fix unicode maintainer

Add support for maintainer in PKG-INFO