Updated to use the new Compass plugin
removed reliance on compass watch for site to run
Fix ratpack-site using compass watch
use consistent versions of compass & jruby in subprojects
transitive dependencies of compass plugin are busted due to bintray mis-configuration
fixed issue with transitive dependencies from the compass plugin
use compass plugin 2.0.4 which lets us install the gems in a shared location for site and manual
Merge pull request #475 from robfletcher/master

Updated to use the new Compass plugin.

Closes #475.