- add logging inside page context
- hiddenSelector to hide dom elements
- screenshotSelector to override selector
- debug option to pause before screenshot
- hide axes, increase padding, for better testing
- add tests for all rotations, placements and boundary types around chart edges
- update existing tests with new changes
- tighten threshold to zero for pixel and overall diff

Updates partition charts to allow for adaptive text color to meet acceptable color contrast ratio. For more information on text contrast see [docs](https://github.com/elastic/elastic-charts/blob/master/docs/0-Intro/1-Overview.mdx#background-colors-and-text-contrast).

BREAKING CHANGE
Adds `background` to the `Theme` object with the `BackgroundStyle` type that accepts a `color` value as a `string. Note text color might be different after changes from this PR, see docs on how to disable `textContrast` in the partition chart config.

Closes #606

Improve eslint to rules to promote best practices and uniformity across the codebase.

fixes #628

This commit adds the screenshot function to partition chart and goal charts

Fix the double rendering caused by ignoring the fact that the container size > 0 needs to be part of the required flags to initialize the rendering process.

fix #690

- Move cyclical constants to separate files
- Move cyclical functions to separate files
- Move some cyclical types into separate files
- Move tests to new locations

# [19.5.0](v19.4.1...v19.5.0) (2020-06-15)

### Bug Fixes

* **tooltip:** show true opaque colors in tooltips ([#629](#629)) ([23290be](23290be)), closes [#628](#628)
* path of stacked area series with missing values ([#703](#703)) ([2541180](2541180))
* remove double rendering ([#693](#693)) ([ebf2748](ebf2748)), closes [#690](#690)

### Features

* **partition:** add 4.5 contrast for text in partition slices ([#608](#608)) ([eded2ac](eded2ac)), closes [#606](#606)
* add screenshot functions to partition/goal ([#697](#697)) ([5581c3c](5581c3c))