Recommand an install from github as rubygems version is deprecated

The current version published on rubygems has SSL verify defaulted to false. Warn users in README and request them to install from Github.

DETAILS:
in lib/force/concerns/connection.rb for force.0.0.1 as published on https://rubygems.org/gems/force:

module Force
  module Concerns
    module Connection
    .....
      # Internal: Faraday Connection options
      def connection_options
        { :request => {
            :timeout => options[:timeout],
            :open_timeout => options[:timeout] },
          :proxy => options[:proxy_uri],
          :ssl => {:verify => false}
        }
      end
    .....
    end
  end
end

The gem published on rubygems https://rubygems.org/gems/force is from October 2013 but the version on github just does not match it: https://github.com/heroku/force.rb/blob/master/lib/force/concerns/connection.rb. There has probably been a gem push from an other version of the source code.