Update README.md, Fix badge 'last commits' (#987)

Author: JingqingZ

README.md

@@ -9,7 +9,7 @@
 
 <!--- [![PyPI Version](https://badge.fury.io/py/tensorlayer.svg)](https://badge.fury.io/py/tensorlayer) --->
 <!--- ![PyPI - Python Version](https://img.shields.io/pypi/pyversions/tensorlayer.svg)) --->
-![GitHub last commit (branch)](https://img.shields.io/github/last-commit/zsdonghao/tensorlayer2/master.svg)
+![GitHub last commit (branch)](https://img.shields.io/github/last-commit/tensorlayer/tensorlayer/master.svg)
 [![Supported TF Version](https://img.shields.io/badge/TensorFlow-2.0.0%2B-brightgreen.svg)](https://github.com/tensorflow/tensorflow/releases)
 [![Documentation Status](https://readthedocs.org/projects/tensorlayer/badge/)](https://tensorlayer.readthedocs.io/)
 [![Downloads](http://pepy.tech/badge/tensorlayer)](http://pepy.tech/project/tensorlayer)