Hamiltonian Cycle (#1930)

* add skeleton code

* add doctests

* add tests for util function + implement wrapper

* full implementation

* add ability to add starting verex for algorithm

* add static type checking

* add doc tests to validation method

* bug fix: doctests expected failing

* Update hamiltonian_cycle.py

* Update hamiltonian_cycle.py

Co-authored-by: Christian Clauss <cclauss@me.com>