Revert "project description in pypi docs (#1172)"

This reverts commit 23b4142.

README.md does not pass readme_renderer, for some reason, and this
blocks sdist uploads to PyPi.

setup.py

@@ -9,9 +9,6 @@
 mod_dir = os.path.join(work_dir, 'src', 'confluent_kafka')
 ext_dir = os.path.join(mod_dir, 'src')
 
-with open(os.path.join(work_dir, 'README.md'), encoding='utf-8') as f:
-    long_description = f.read()
-
 INSTALL_REQUIRES = [
     'futures;python_version<"3.2"',
     'enum34;python_version<"3.4"',
@@ -83,8 +80,6 @@ def get_install_requirements(path):
       description='Confluent\'s Python client for Apache Kafka',
       author='Confluent Inc',
       author_email='support@confluent.io',
-      long_description=long_description,
-      long_description_content_type='text/markdown',
       url='https://github.com/confluentinc/confluent-kafka-python',
       ext_modules=[module],
       packages=find_packages('src'),