v1.1.0

Refactor the code, made available on PyPI.

Refactor the assim_tools module to use classes for components of the core assimilation algorithm.

• Available Assimilators: ETKF, TopazDEnKF, EAKF

• Available Updators: Additive and Alignment

• Misc. transform funcs: null, scale_bandpass

Added readthedocs documentation pages.

Added a few examples of use cases: QG model benchmarking of filter performance