text: Title: Cleanup Normalizer Converter Code
  Body: We have the original draft of the normalizer code uploaded in [this branch](https://github.com/microsoft/hummingbird/tree/cleanup/normalizer). All credit here goes to @scnakandala, the original author and brains behind this.
  
  It contains an un-edited implementation of SklearnNormalizer [here](https://github.com/microsoft/hummingbird/blob/cleanup/normalizer/hummingbird/ml/operator_converters/normalizer.py).
  
  There is a single test file [here](https://github.com/microsoft/hummingbird/blob/cleanup/normalizer/tests/test_sklearn_normalizer_converter.py) that needs to be cleaned up and passing.
  
  