convert kebab-case to camelCase in testProps for browsers that don't have @supports support

[patrickkettner]

fixes #1322

[stucox]

Turns out this fix had the knock-on effect of enabling testProp() and testAllProps() to accept kebab-case too – which is nice.

Tests are failing because it appears we had an explicit test to verify that kebab-case isn’t supported:

  // test/js/unit.js:L413
  equal(false, Modernizr.testProp('font-size'), 'Nobody supports font-size');

  // test/js/unit.js:L440
  equal(false, Modernizr.testAllProps('font-size'), 'Nobody supports font-size');

I’ve raise a PR against your branch to update the tests and the comments at the top of the relevant files in src/. Have also (slightly prematurely) updated the release notes.

[stucox]

Cheers bro!