Speed up builds
Added `rollup-plugin-progress` to compare compilation times between rollup & webpack on the simple `react-sketchapp` examples — feels like rollup is significantly slower the webpack 

### skpm
**initial build** ~3500ms
**incremental builds w/ watch** ~1500ms
**incremental builds w/ watch, + disabling `treeshake`** ~1000ms

### webpack
**initial build** ~3500ms
**incremental builds** ~60ms

Is there a bug in the skpm config? Is there a better `watch` we can use? Should we disable treeshake?