ENH: flake-8 standards

# Description
Need to update flake-8 standard with the other pysat projects

## Potential Impact
May need major rewrite of portions of code

## Potential solution(s)
- [ ] Add hacking and docstring checks
- [ ] Update code standards accordingly
- [ ] remove cap on flake8, fix how ignore statements are handled

# Alternatives
lower standards

# Additional context
follow on from #39. 