Add Makefile

Add a trivial makefile that creates svg-animations.js by appending
web-animations.js and smil-in-javascript.js
Merge pull request #3 from ewilligers/makefile

Add Makefile
Implement simple SVG animations via Web Animations

This code illustrates how simple SMIL animation elements with no timing instructions (other than duration and repeat count) can be handled directly using Web Animations.

For now, we assume no events or sync-based dependencies.

Test with the Blink CL that has native animation elements disabled -
https://github.com/smil-in-javascript/blink/pull/2