Just dependency updates, nothing jazzy this time!

A much smaller release focusing on some nice to haves:

• The workflow now automatically increments the cache busting variable when gulp is used,
• Add a SASS path functionality,
• JS Unit tests are now linted,
• JS linting is now ran on build (but doesn't stop the task if there are warnings),
• Add basic print styles,
• Dependency updates.

NOTE: Yarn support has been removed at this time due to issues with Travis-CI and other CI services.

• Add full Yarn support,
• Update dependencies.

Fixes an issue with functions used in _variables.scss not working

This is the biggest update to this workflow since the project began. Many features which have been pending for a long time have been implemented.

• Add Mocha & Chai Javascript user testing,
• Refactor SCSS to use ITCSS,
• Updated SCSS code with many new features such as typography, spacing and helpers,
• Add sitemap.xml generation,
• Add robots.txt generation,
• Add tota11y accessibility checker task,
• Add JavaScript sourcemaps,
• Add Commitizen support,
• JavaScript now uses ES6 modules,
• SVG icons now use SVGGO to compress icons,
• Add new 'config' folder to configure the workflow,
• Add example favicon, pinned tab & mobile app icons,
• Updated dependences.

NOTE: The .node-version file was removed from the workflow due to problems when having multiple versions of node installed on the same machine.

• Renamed the workflow to garrus,
• Updated dependencies.

• Add a .node-version file for avn,
• Fix babel-register startup error,
• Update dependencies.

Hotfix for normalize.css not importing correctly.

Mainly some housekeeping, but with one or two nice additions. Dependencies move fast!

• Added stylefmt to 'auditcode' task to automatically fix SCSS linting code,
• Updated to use normalize.css v4 and pull it in via npm for easy updating,
• Fixed handlebars helpers not working in Metalsmith and added an example,
• Remove the need for eyeglass, this should help with Windows machines,
• Tweaks to svgsprite task to improve error logging and SVG processing,
• Updated all dependencies.

• Reverted to gulp-sass 2.2.0 as 2.3.0 has errors on Windows,
• Fixed icon partial path variable.