Downgrade fakefs, we've discovered a bug. I'll be working on a minimal test case to resolve this.

Also add a new set of tests that were created when debugging this fakefs issue.
Rubocop wants a UTF-8 encoding in the Gemfile
Refresh support (PUP-2452)

* Notify/subscribe support in puppet >=3.6
* Minor tidying around the features being set
* SVG build icon
* Tweak travis ruby versions