Add ruby 2.4.1 to main-ruby-go image in preparation for Ruby bump
Add ruby 2.4.1 to main-ruby-go image in preparation for Ruby bump

[#150612247](https://www.pivotaltracker.com/story/show/150612247)

Signed-off-by: Shatarupa Nandi <3efeaa499e3e1d586e0cf648346ba222fe46816b@pivotal.io>

barthy1/bosh,barthy1/bosh,barthy1/bosh,barthy1/bosh