Pyperf

--------------------------

* pyperf ref:`compare_to command <compare_to_cmd>` now supports the
``--table-format`` option which can designate the table format
between reST and markdown.

--------------------------

* ``--track-memory`` option now supports macOS by using ``psutil``.
* Added ``--copy-env`` command line option that inherits all environment variables.
* The development branch ``master`` was renamed to ``main``.
See https://sfconservancy.org/news/2020/jun/23/gitbranchname/ for the
rationale.

--------------------------

* The :ref:`compare_to command <compare_to_cmd>` now computes the geometric
mean.
* The :ref:`compare_to command <compare_to_cmd>` no longer displays
percentages: display less numbers to make the output easier to read. Also,
percentage were almost the same values than the xxx faster or xxx slower
values, but rounded differently which introduced confusion.
* Project moved to https://github.com/psf/pyperf/
* system command now only emits a warning rather than failing with a hard error
if it fails to get or set the frequency of a CPU.
* The pyperf project is now covered by the `PSF Code of Conduct
<https://www.python.org/psf/codeofconduct/>`_.

--------------------------

* Drop Python 2 support. Use pyperf 1.7.1 if you still need Python 2.7
support.
* Remove ``python_unicode`` metadata.
* pyperf.perf_counter() is now deprecated: use time.perf_counter() directly.

--------------------------

* Support Python 3.8: ``time.clock()`` no longer exists.

--------------------------

* metadata: add ``python_compiler``
* Windows: inherit ``SystemDrive`` environment variable by default.
Contribution by Steve Dower.
* Fix tests on ARM and PPC: cpu_model_name metadata is no longer required
on Linux.
* tests: Do not allow test suite to execute without unittest2 on Python2,
otherwise man failures occur due to missing 'assertRegex'.
Contribution by John Vandenberg.
* doc: Update old/dead links.
* Travis CI: drop Python 3.4 support.