TrainerRed151

The README references `KeyHelper.generateLastResortKey()`, but `KeyHelper` has no such function: ``` AttributeError: type object 'KeyHelper' has no attribute 'generateLastResortKey' ```

Faster sha256 function

1

Calling `hashlib.sha256` directly with the `hexdigest()` output is an order of magnitude faster. Before change: ``` >>> timeit.timeit("import cryptos; cryptos.sha256('foo')", number=1000) 0.01851644799999974 ``` After change: ``` >>> timeit.timeit("import cryptos; cryptos.sha256('foo')",...