Overlapping partial Nyans


As you can see, there seems to exist a condition where multiple fast initial messages creates multiple partial Nyans before the one that ends up working/tracking the whole progress.

I'm on v1.0.3 and my dev server config is:

``` js
devServer: {
quiet: false,
noInfo: false,
stats: {
assets: false,
colors: true,
version: false,
hash: false,
timings: false,
chunks: false,
chunkModules: false
}
},
```

Awesome plugin, by the way! :grin: