Infertrade

Change log:

- update yaml build to use Ubuntu 18.04

Change log:

- adds Sphinx documentation.

Change log:

- removal of unused utility functions
- expanded performance unit test
- arg hints and linting

Change log:

- new regression rules.
- updated arg hints.

Change log:
- moved Apache licences to single line comments rather than in docstrings (to assist IDEs and auto-documentation)
- moved the the scikit_allocation_factory function from infertrade/algos/community/allocations.py to infertrade/utilities/operations.py
- minor readme update and refactorings

Change log:

- adds a Chande Kroll stop indicator;
- incorporates a few other miscellaneous updates.