Fix authlib PyPI link, and codecov badge
# Authlib
<a href="https://travis-ci.org/lepture/authlib"><img src="https://api.travis-ci.org/lepture/authlib.svg?branch=master" alt="Build Status"></a>
-<a href="https://codecov.io/gh/lepture/authlib?branch=master"><img src="https://codecov.io/gh/lepture/flask-wtf/branch/master/graph/badge.svg" alt="Coverage Status"></a>
-<a href="https://pypi.python.org/pypi/mistune/"><img src="https://img.shields.io/pypi/wheel/authlib.svg?style=flat" alt="Wheel Status"></a>
+<a href="https://codecov.io/gh/lepture/authlib?branch=master"><img src="https://codecov.io/gh/lepture/authlib/branch/master/graph/badge.svg" alt="Coverage Status"></a>
+<a href="https://pypi.python.org/pypi/authlib/"><img src="https://img.shields.io/pypi/wheel/authlib.svg?style=flat" alt="Wheel Status"></a>
Authlib is a ready to use authentication client and server for
OAuth 1, OAuth 2 and more.
