add genCss task as part of deploying master to live site
As part of the automated build to put the master branch 'live' onto the server addressed at http://dev.beta.embl.org/guidelines/visual-framework/dev-docs/ we need to add the gulp genCss
task so that it has the compiled CSS per pattern. This makes it possible for teams to easily 'grab' a pattern from the live site and implement, if so needed.