Rewrite python unit tests: step 1
Rewrite python unit tests: step 1

Test Plan: unit tests

Reviewed By: @alikhtarov

Differential Revision: D2383553
facebook/mcrouter,is00hcw/mcrouter,nvaller/mcrouter,facebook/mcrouter,easyfmxu/mcrouter,synecdoche/mcrouter,synecdoche/mcrouter,yqzhang/mcrouter,zhlong73/mcrouter,is00hcw/mcrouter,facebook/mcrouter,easyfmxu/mcrouter,is00hcw/mcrouter,easyfmxu/mcrouter,zhlong73/mcrouter,nvaller/mcrouter,reddit/mcrouter,nvaller/mcrouter,zhlong73/mcrouter,synecdoche/mcrouter,reddit/mcrouter,reddit/mcrouter,easyfmxu/mcrouter,yqzhang/mcrouter,reddit/mcrouter,synecdoche/mcrouter,facebook/mcrouter,yqzhang/mcrouter,nvaller/mcrouter,zhlong73/mcrouter,is00hcw/mcrouter,yqzhang/mcrouter