BRIE: The Barrier Inlet Environment model

This is the python version of the BarrieR Inlet Envrionment (BRIE) model written by Jaap Nienhuis and Jorge Lorenzo Trueba. The matlab to python conversion was performed by Katherine Anarde. Eric Hutton worked to wrap the model with a basic model interface, reorganized the many model components into classes (i.e., The Alongshore Transporter), which now allows for dynamical testing of the alongshore transporter model (see the Jupyter Notebook).