master Go build errors resolved by removing deps.

These dependencies were accidentally committed when the tests were
run for other Go frameworks (revel/webgo/falcore) with the $GOPATH
environment variable being set to 'FrameworkBenchmarks/go'. This
caused every build dependency to get lumped into go's folder, which
ended up causing build/run errors for Go during tests.
Removing these folders is fine as everything required to run Go will
be rebuilt/fetched when the go tests start.
Merge remote-tracking branch 'ratpack/master'
Remove square brackets from json() argument.