ES6 and mouse wheel bug fix

Converted some of the code to ES6
Fixed a bug where using the mouse wheel while the cursor is above the custom scrollBar area did not work.

Fixed minimum handle size

When visible area to scroll area ratio is very low, the scroll handle should get a minimum height (like the real handle displayed by the browser).
This is fixed in this patch
This patch also allows setting the minimum handle height through props

JSX and remove Lodash

Replace React-Templates with JSX, and remove Lodash dependency

Patch for blocking selection

prevent default behavior of mousemove event while dragging scroll handle

autoprefix css, and block selection while dragging the scroll handle

Added autoprefixer to the project, mainly to allow user-select: none
Refactored the css so the content container will get user-select:none while the scroll handle is being dragged, thus preventing unwanted selection of content

Remove jQuery dependency

Events are now added with native addEventListener
I've noticed mousemove event listener on the document node doesn't always work well in IE-10 or older, so I've waited with this change, but I guess it's time to move on from those browsers.

Tests and lodash 4

Support lodash 4, by removing the use of _.pick
Add unit tests, and karma integration

v1.0.2

Readme updates

First major version for open source

Custom scroll is now available in UMD and commonJS
UMD file is minified
Removed a ton of old dependencies
Removed usage of grunt, simple build with npm scripts (run npm start)