issue warning with unexpected keys in input

What's Changed

• ci: add commitizen by @elmotec in #12
• ci: fixed documentation references to master by @elmotec in #13
• Create python-package.yml by @elmotec in #15
• ci: add specific versions in *requirements.txt by @elmotec in #16
• ci: add coverage back by @elmotec in #17
• ci: turn off codecov verbosity by @elmotec in #18
• ci: auto publish to pypi by @elmotec in #19
• feat: issue warning with unexpected keys in input by @elmotec in #20

Full Changelog: v0.14.0...v0.15.0

Improved circle packing heuristic

The heuristic should be good enough for #8. Still some work to be done to implement A1.5.

Added sensible Circle.ex value when input is scalar input values

Scalar input data like [0, 1, 2 ...] would lose the information related to the input values when converted to Circle even after we added the ex dictionary. The input values is now stored in the ex dict when the input is a simple scalar value. That allows for downstream to display sensible text defaults when drawing the circles.

See https://github.com/elmotec/circlify#example for an example.