Remove reference to golang 1.4 in README
Remove reference to golang 1.4 in README

Signed-off-by: Amin Jamali <828117156edecfc83d6e458626bc6ccd219cba0e@pivotal.io>

cloudfoundry/garden-windows,cloudfoundry/garden-windows,cloudfoundry-incubator/garden-windows,cloudfoundry/garden-windows,cloudfoundry-incubator/garden-windows,cloudfoundry-incubator/garden-windows