feat(gulp): copy fonts-awesome files
feat(bower): save font-awesome to project dependencies
feat(flow): add d3 plugin 'sankey'

* http://bost.ocks.org/mike/sankey/
* https://github.com/d3/d3-plugins/tree/master/sankey
style(js): change indentation, correct linting error
docs(install): add basic install commands
style(js): correct linting errors
refactor(css): change entities/arrow colors
refactor(d3): store geoJSON feature into variable
feat(d3,svg): add marker-end to <path>
feat(d3,data): build array list of centres for sankey plugin
feat(d3,data): build links array list for sankey plugin
feat(d3,route): add class attribute with from/to centre