- update to 4.0.0:
* builddoc: Treat '[pbr] autodoc\_tree\_excludes' as a multi-line opt
* update parse test to use reliable comparison
* Make docs on env vars a little clearer
* Updated from global requirements
* future-proof invocation of apidoc
* emit warning correctly
* deprecations: Deprecate support for '-py{N}' requirements
* doc: Minor rework of usage doc
* doc: Rework features doc
* Support v version
* Deprecate testr and nose integration
* tests: Increase coverage of requirements parsing
* trivial: Move packaging tests to test\_packaging
* Put test-requirements into an extra named 'test'
* Support Description-Content-Type metadata
* Avoid tox\_install.sh for constraints support
* Test on Python 3.6
* Support PEP 345 Project-URL metadata
* Remove setting of version/release from releasenotes
* Use 'build\_reno' setuptools extension if available
* Remove unnecessary 'if True'
* Discover Distribution through the class hierarchy
* Add reno for release notes management
* Remove support for command hooks
* Remove dead code
* Deprecate support for Sphinx < 1.6
* builddoc: Use '[sphinx\_build] builders' with Sphinx < 1.6
* Remove win32/nt checks for wrapper script gen
* Remove py26 support