Allow download with specific platform and --no-deps

Add a coverage job for Python 3

The links to the mailing lists contained a trailing '>',
resulting in a 404 error.

* misc: switch docs badge to latest

* misc: Minor cleanups in README

Move all the links to the botton, rewrap lines.

docs: fix some indentation issues in quickstart

tests: don't check the actual sequence in test

* Add a global option to disable colors

 This is a fix for issue #2449

 All it does is simply add a global option --no-color

 Internally it switches ColorizedStreamHandler to StreamHandler if
 this flag is detected.

* Fix lint errors

 * not sure it makes the code more readable though ...

* Fix typo

* Choose logging class before assigning

 * As requested per review
 * Make the code shorter and easier to follow

* Be polite to followers, add commas

* Add functional test for the --no-color output

* Better detection of windows

* Fix fragile tests - can't trust script --quiet

 * The version found in Travis-CI does not respect this flag
   It added a prefix line and suffix line found if one does not
   add the flag --quiet (script from util-linux 2.26.2).

   As such the out  put is:

     Script started on Fri 27 Oct 2017 07:17:30 AM CEST
     \x1b[31mCannot uninstall requirement noSuchPackage, not installed\x1b[0m\n

     Script done on Fri 27 Oct 2017 07:17:31 AM CEST

  With this change, the test should pass, and is hopefully more stable.

* Simplify testing for color or no-color

- Wheel doesn't have a public API
- Reword warning about installing into a running interpreter

pip uninstall no longer aborts if a package is not installed; instead
it prints a warning that the package is not installed and it is
skipping the uninstallation of it for this reason.

* Update distlib to 0.2.6
* Update six to 1.11.0
* Update pkg_resources (via setuptools) to 36.6.0.

Fix the documentation build

Installed files are recorded by Pip in the order the underlying tool
(Distutils, Setuptools, ...) recorded them.

Unfortunately, at least Setuptools doesn't record them in a
deterministic order in the case of a directory being installed, as it
uses os.walk to find the list of files.

We could fix all those underlying tools to record their files in a
deterministic order in all situations. But fixing it once here in Pip
for all tools is certainly simpler and more future-proof.

This makes the installation more reproducible, and therefore more
verifiable.

* Add `--retry-status <HTTP code>` to allow specifying custom HTTP staus codes to retry on.
This is useful for AWS S3 or Cloudflare, which at times return codes other than 503 for
itermitent failures.

* stripping option related code, hardcoding the statuses

* Reword the news file

* changing ndash to regular ascii dash

* Add failing tests for issue #1139 re: --force-reinstall.

* Address issue #1139: make --force-reinstall not require --upgrade.

* Address review comments.

* Address @xavfernandez's review comments.

This makes the new tests not require network access.

RequirementPreparer no longer takes Resolver as argument in any of its methods and directly takes the reference of the values it actually needs.