Export Helpers

[casesandberg]

This PR gives access to the internal helper functions we use:

import { getContrastingColor } from 'react-color/lib/helpers'

Closes #498

[przemyslawzalewski]

I was just browsing the latest release notes and inspecting the changed code and got curious about this as I couldn't find any spec about export default exports. It seems that this is some kind of Babel magic or a coincidence that Babel-generated code just exports a common-js implicit module.exports variable as the default export.

Please see the example and the generated code on the Babel REPL:
https://babeljs.io/repl#?browsers=&build=&builtIns=false&spec=false&loose=false&code_lz=KYDwDg9gTgLgBAYwgOwM7xHAvHArAbgChDRJZEV04BPbOANiMIHpm4BVZJAW2-GXgwAFgEtUcAG4BDADYiAJhXnA4MCHFTAVwlQHVoMxUhkypYTahZskaeKWgxxOAEQRuAc2fF75ZQDMpAFcZO3AHVCA&debug=false&forceAllTransforms=false&shippedProposals=false&circleciRepo=&evaluate=false&fileSize=false&timeTravel=false&sourceType=module&lineWrap=true&presets=es2015%2Creact%2Cstage-2&prettier=false&targets=&version=7.7.7&externalPlugins=

As the exports is not a reserved keyword, another export can be named exports to make this scheme to fail horribly exporting that binding, not "all the named exports" as intended by the "accidental syntax".

Please see the generated code: https://babeljs.io/repl#?browsers=&build=&builtIns=false&spec=false&loose=false&code_lz=KYDwDg9gTgLgBAYwgOwM7xHAvHArAbgChDRJZEV04BPbOANiJPGniTXlNdToCIIAtgHNexLuQAmwAGYBDAK4AbTi1iogA&debug=false&forceAllTransforms=false&shippedProposals=false&circleciRepo=&evaluate=false&fileSize=false&timeTravel=false&sourceType=module&lineWrap=true&presets=es2015%2Creact%2Cstage-2&prettier=false&targets=&version=7.7.7&externalPlugins=

@casesandberg - I think an explicit default export of all the named exports is way better as it does not rely on Babel quirks and it is a valid piece of ES code. Are PRs welcome?

[casesandberg]

Good catch! We are working on the next major release right now which is fully ES6, so it will not have these problems going forward. I appreciate your thoroughness, however!