Support current PyMySQL version

[ymj4023]

can the aiomysql pymysql>=0.9.3?

[suiyuex]

in this file, should support

[ghost]

Question is about >=0.9.3 while the file states PyMySQL>=0.9,<=0.9.3

In any case, can somebody update release on pypi with those reqs? Pypi still insists on <=0.9.2.

[fabaff]

PyMySQL is already 0.10.1.

The complete release pinning should be removed and the relevant functions covered by unit tests as there is no proper release cycle for aiomysql, see also #466

[fabaff]

This issue was not addressed by 0.0.21.

[long2ice]

recommended asyncmy

[suiyuex]

@long2ice nice