Merge branch 'release/1.0.2'
Specify the PyMySQL version we can work with.
Merge pull request #4 from LeeXiaolan/pymysql-compatibility

Specify the PyMySQL version we can work with.
add changelog
Merge branch 'master' into develop
Merge branch 'develop' of https://github.com/hongqn/umysqldb into develop
release 1.0.3
rename test case and fix the unit test
integrate with Travis CI