Added binary exponentiaion with respect to modulo (#1428)

* Added binary exponentiaion with respect to modulo

* Added miller rabin: the probabilistic primality test for large numbers

* Removed unused import

* Added test for miller_rabin

* Add test to binary_exp_mod

* Removed test parameter to make Travis CI happy

* unittest.main()  # doctest: +ELLIPSIS   ...

* Update binary_exp_mod.py

* Update binary_exp_mod.py

* Update miller_rabin.py

* from .prime_check import prime_check

Co-authored-by: Christian Clauss <[email protected]>