Breaking Changes:
- All analysis objects must now call a `run()` function to execute the analysis.
- Removed ability to call limit state function if passed as a string; use a function or lambda instead
- Default now is to not show printed results; use `options.setPrintResults(True)` to revert to previous behaviour. This makes the default behaviour better for using pystra in notebooks.
Updates:
- Added the Direct Differentiation Method (per https://github.com/pystra/pystra/issues/30 ), including a new example and tests.
- Progress on eliminating star imports
- Minor: changing `pr` to `ra` as shortform for pystra
- new `AnalysisObject` base class from which all probability estimators inherit
- Refactored `LimitState` so it now contains the evaluations of the LSF
- Multiple other minor tweaks.
- Update doc build requirements and fix some warnings