Add package.el required comments

These are the minimum things needed to make the package friendly for
package.el. As part of this I've changed the one line description to be
more easily scanned in a package list.
Add dependency on Evil

Pin this package to *at least* the current stable Evil (1.0.8 on
Marmalade at the time). This is so it will auto-install the dependencies correctly.
Release as 1.0.0

It's the first stable version.
Add provide definition

This makes the script more easily installable than attempting a direct
load of the file, e.g:

    (require 'colemak-evil)
Merge pull request #25 from bradleywright/package-format

Make colemak-evil installable via package.el