Feature/dependency and build fix

[apertureless]

Dependency Cleanup

• Updated to current babel packages which are scoped with @babel
• Added @babel/preset-env to automatically polyfill
• Removed old babel presets

Build Script

Now there are only two dist files

• vue-chartjs.js
• vue-chartjs.min.js

With the webpack external fix, there is no need for two different builds.
Chart.js is defined as an external and peerDependency.

If you're using vue-chartjs with Webpack no actions are required.
If you're using vue-chart in the browser you will need to add the Chart.js CDN script.