Touch 'egg-info' directory

Pin against sphinx 1.8.0 due to sphinx-doc/sphinx#5417.

build_meta.get_requires_for_build_sdist does not include wheel

Suppress warnings in importer.find_module.

Remove compatibility shim for bytes type

link to setuptools doc

The type bytes is available on all supported Pythons. Makes the code
more forward compatible with Python 3.

the wheel package is not required to build a source distribution

Resolves #1474.

Fix for Unicode handling in PEP 518 backend

setuptools: fix regression with `egg_info` command

Ensure version is tagged only once.

'tox' determines whether a package should be rebuilt by comparing the
timestamp of the package's 'egg-info' directory and its 'setup.py' or
'setup.cfg' files [1][2]. Unfortunately this checks the 'egg-info'
directory itself, which is not updated, unlike the contents of that
directory. This means that 'tox' will always rebuild the package once
one of the two setup files has been updated.

While this is clearly a bug in 'tox' that should be fixed separately,
there is merit in using this as a heuristic so enable it.

[1] https://github.com/tox-dev/tox/blob/3.1.0/src/tox/venv.py#L253-L257
[2] https://github.com/tox-dev/tox/blob/3.1.0/src/tox/venv.py#L221-L244Signed-off-by: Stephen Finucane <stephen@that.guru>

There's no reason these should be executable.
Signed-off-by: Stephen Finucane <stephen@that.guru>

These are commonly used for testing purposes.
Signed-off-by: Stephen Finucane <stephen@that.guru>