v2.0.0:Updated to Python 3 + pyqt5

This is the first version of the project to be transplanted to Python3+PyQt5. The old function is the same as the previous version, adding some supplementary contents in the tutorial.

v1.0.0:The final version built in python2.7 + PyQt4

This is the last update using python2.7 + PyQt4, and all subsequent code will be updated to python3 + pyqt5.