Add basic Python tests for Primes and Sieve
Add basic Python tests for Primes and Sieve

* Make sure an exception is thrown if upper_bounds is exceeded
* 0 is not in primes list
* Number of prives asked for is given
* Sieve upper bounds >= limit

Michael-F-Bryan/rust-ffi-guide,Michael-F-Bryan/rust-ffi-guide,Michael-F-Bryan/rust-ffi-guide