Add a test for timing functions that map to values outside the range [0, 1]
Add a test for timing functions that map to values outside the range [0, 1]

beni55/web-animations-js-legacy,beni55/web-animations-js-legacy,dstockwell/web-animations-js,web-animations/web-animations-js-legacy,dstockwell/web-animations-js,web-animations/web-animations-js-legacy,birtles/web-animations-js,birtles/web-animations-js,beni55/web-animations-js-legacy,beni55/web-animations-js-legacy,birtles/web-animations-js,web-animations/web-animations-js-legacy