- update to 7.1.2:
* Don't raise an error if pip is not installed when checking for the latest pip
version.
* Check that the wheel cache directory is writable before we attempt to write
cached files to them.
* Move the pip version check until *after* any installs have been performed,
thus removing the extraenous warning when upgrading pip.
* Added debug logging when using a cached wheel.
* Respect platlib by default on platforms that have it separated from purlib.
* Upgrade packaging to 15.3.
* Normalize post-release spellings for rev/r prefixes.
* Upgrade distlib to 0.2.1.
* Updated launchers to decode shebangs using UTF-8. This allows non-ASCII
pathnames to be correctly handled.
* Ensured that the executable written to shebangs is normcased.
* Changed ScriptMaker to work better under Jython.
* Upgrade ipaddress to 1.0.13.
* Allow constraining versions globally without having to know exactly what will
be installed by the pip command. :issue:`2731`.
* Accept --no-binary and --only-binary via pip.conf. :issue:`2867`.
* Allow ``--allow-all-external`` within a requirements file.
* Fixed an issue where ``--user`` could not be used when ``--prefix`` was used
in a distutils configuration file.
* Fixed an issue where the SOABI tags were not correctly being generated on
Python 3.5.
* Fixed an issue where we were advising windows users to upgrade by directly
executing pip, when that would always fail on Windows.
* Allow ``~`` to be expanded within a cache directory in all situations.
* Fixed a regression where ``--no-cache-dir`` would raise an exception, fixes
:issue:`2855`.