* initial commit of Roger's contrib
* add the new file to the headers list
* clang-format
* stub of the python wrapper
* code added for testing
* code added for testing
* add LeaderPicker.seq.h
* default pickSize value
* first crude python wrapper
* Add C++ tests for the LeaderPicker
combine the thread and non-thread versions
* that was not really a test
* support providing a functor from Python
* no longer need the .seq header
* temporarily disable the threaded version to allow CI runs to pass
* some refactoring and cleanup
