* [TD-4752]<feature>: python connector support nanosecond.
* [TD-4752]<feature>: support nanosecond in test framework.
return integer for nanosecond in connector since python does not support nanosecond yet.
* [TD-182]<enhance>: use single repo for python connector
Remove code for each platform and build up one single python code base
for windows/osx/linux platforms and python2/python3 runtime.
* [TD-182]<enhance>: remove redundant code in python connector
* [TD-4149] <fix>: fix python connection config error