pip install spynner
报错 src/png_io.c:3:17: error: png.h: No such file or directory
解决：yum install libpng libpng-devel
再pip install spynner
安装成功：
Running setup.py install for beautifulsoup4
Running setup.py install for spynner
Successfully installed autopy-0.51 beautifulsoup4-4.3.2 spynner-2.19 unittest2-1.0.1