change licence to markdown
Update README.md
Configure poltergeist to allow any SSL protocol

This might help with the loading of assets.
Also makes the version of poltergeist explicit
upgrade ruby to 2.1.4
Merge pull request #150 from bitzesty/ruby-2.1.4

upgrade ruby to 2.1.4
Merge branch 'master' of github.com:alphagov/trade-tariff-frontend into tariff-docker