2.0.0

A complete rewrite using vanilla javascript, removing the jQuery dependency. Big thanks to @brodiefarrell for this release.

• IE 7-9 browser support removed, please use 1.4.0 if you require IE browser support
• Rewritten with the aim to have 100% feature parity and backwards compatibility with version 1.4.0
• Support for deeply nested submenus 3+ levels
• Updated Grunt install to modern supported version
• Demo file updated to work with new version
• Removed .pushy-link CSS class
• Updated #container to .container
• Removed data-container-selector