1. Delete repeat_open_url_n_read, for the reason that it's duplicated in function with open_url_n_read
2. Reordered existed test cases
3. new test cases for post_with_response
4. Use port URL haijia.bjxueche.net:81 instead of facebook in timeout tests
1. Abstract class Role and its meta class
2. Unit tests of customized creation of subclasses of Role and Logger
1. New class method for adding property to Role and its sub classes
2. Draft version of Driver