Update devDependencies

[aminya]

Description of the change

• This PR updates the devDependencies of event-kit.
• It uses babel-preset-atomic as the babel preset.
• Allows the non-transformed code to be included in the npm package (lib folder).

It uses my joanna fork which supports parsing new JavaScript. If you merge that PR, we can use the package itself. atom/joanna#12.

Benefits

• By using non-transformed code, users can use ES6 classes. This is useful since babel transformation converts the ES6 classes to prototypical functions. By including the lib folder, the users can opt into using the ES6 class code by requiring the event-kit/lib/event-kit

• Allows us to modernize event-kit code in the future PRs (see Optimizations (Parcel + CompositeDisposable + Disposable + Emitter) #52)

Verification

All the tests pass:

[aminya]

@darangi @sadick254 Consider this and #52 if you had time :). Pretty straight forward updates.