2.0.0

This release adds:

• Badges! (b0a98e7 and 6ac6928)
• Linting with ESLint (c49a382)
• Travis CI to automatically lint... with ESLint (36a5519)
• JSDoc for types (dead512)
• Breaking change: Moved Shortcut#imageURL to Shortcut#icon.downloadURL (a01a88a)
• Added details for a shortcut icon's color and glyph (a01a88a)
• A version bump! (82dce0d)