Add editorconfig to project, add Changelog, update npm-deps

Hey,

just updated deps and whilst doing that I recognized there are some things I’d like to see addressed: 

Currently there’s a mix of spaces and tabs in the project, no line ending conventions etc. Therefore I added a [.editorconfig](http://editorconfig.org/) file which helps ensuring it. I preset to spaces but am happy to change if you wish to switch to tabs entirely. After that I’m happy doing another PR changing all files according to it.

I also didn't see any changelog which helps people to see what changed over versions. I added a file now.

Lastly, I updated the npm modules to their latest versions.


If you have feedback or don't want all the things in here, let me know :)
Cheers!