Render markdown readme on PyPI (#6004)

* Render markdown readme on PyPI

PyPI now supports GitHub-flavored Markdown descriptions
(https://blog.thea.codes/github-flavored-markdown-on-pypi/),
so there's no need to convert the README to rst with pypandoc
any more.

* Remove readme checking

Checking markdown descriptions is not necessary.
See https://github.com/pypa/readme_renderer#markdown

* Upgrade twine

.travis.yml

@@ -32,11 +32,6 @@ matrix:
           - tox --installpkg ./dist/djangorestframework-*.whl
           - tox  # test sdist
 
-      - python: "3.6"
-        env: TOXENV=readme
-        addons:
-          apt_packages: pandoc
-
     exclude:
       - { python: "2.7", env: DJANGO=master }
       - { python: "2.7", env: DJANGO=2.0 }

requirements/requirements-packaging.txt

@@ -2,13 +2,7 @@
 wheel==0.30.0
 
 # Twine for secured PyPI uploads.
-twine==1.9.1
+twine==1.11.0
 
 # Transifex client for managing translation resources.
 transifex-client==0.11
-
-# Pandoc to have a nice pypi page
-pypandoc
-
-# readme_renderer to check readme syntax
-readme_renderer

setup.py

@@ -8,15 +8,8 @@ from io import open
 
 from setuptools import find_packages, setup
 
-try:
-    from pypandoc import convert_file
 
-    def read_md(f):
-        return convert_file(f, 'rst')
-except ImportError:
-    print("warning: pypandoc module not found, could not convert Markdown to RST")
-
-    def read_md(f):
+def read(f):
     return open(f, 'r', encoding='utf-8').read()
 
 
@@ -32,10 +25,6 @@ version = get_version('rest_framework')
 
 
 if sys.argv[-1] == 'publish':
-    try:
-        import pypandoc
-    except ImportError:
-        print("pypandoc not installed.\nUse `pip install pypandoc`.\nExiting.")
     if os.system("pip freeze | grep twine"):
         print("twine not installed.\nUse `pip install twine`.\nExiting.")
         sys.exit()
@@ -56,7 +45,8 @@ setup(
     url='http://www.django-rest-framework.org',
     license='BSD',
     description='Web APIs for Django, made easy.',
-    long_description=read_md('README.md'),
+    long_description=read('README.md'),
+    long_description_content_type='text/markdown',
     author='Tom Christie',
     author_email='tom@tomchristie.com',  # SEE NOTE BELOW (*)
     packages=find_packages(exclude=['tests*']),

tox.ini

@@ -5,7 +5,7 @@ envlist =
        {py34,py35,py36}-django20,
        {py35,py36}-django21
        {py35,py36}-djangomaster,
-       dist,lint,docs,readme,
+       dist,lint,docs,
 
 [travis:env]
 DJANGO =
@@ -50,8 +50,3 @@ commands = mkdocs build
 deps =
        -rrequirements/requirements-testing.txt
        -rrequirements/requirements-documentation.txt
-
-[testenv:readme]
-commands = ./setup.py check -rs
-deps =
-       -rrequirements/requirements-packaging.txt