Auxo

[AmberLJC]

Why are these changes needed?

Auxo implementation merge.

Checks

• [x] I've included any doc changes needed for https://fedscale.readthedocs.io/en/latest/
• [x] I've made sure the following tests are passing.
• Testing Configurations
  • [x] Dry Run (20 training rounds & 1 evaluation round)
  • [ ] Cifar 10 (20 training rounds & 1 evaluation round)
  • [x] Femnist (20 training rounds & 1 evaluation round)