fixed npm audit issues 

bumped version 

merged john-doherty#75 changes and bumped minor version 

bumped version to 1.6.0 to push to npm 

bumped version 

bumped minor version to update docs 

updated chrome driver to 2.28.0, should fix john-doherty#8 

bumped minor version the right way this time! 

added helpers.getPseudoElementBeforeValue and helpers.getPseudoElemen… …tAfterValue methods

tweaked readme to ensure build status showing on npm