restrict sinatra to 1.3.X family; otherwise get - undefined method `consumes' for VCAP::CloudController::Controller:Class

I updated my ccng to HEAD in my cf-release deployment, recreated the Gemfile.lock (due to a conflict after applying a patch), and I got this error below. There is a new sinatra that we do not want to allow just yet.

```
==> /var/vcap/sys/log/cloud_controller_ng/cloud_controller_ng.stderr.log <==
/var/vcap/packages/cloud_controller_ng/cloud_controller_ng/vendor/bundle/ruby/1.9.1/gems/sinatra-1.4.3/lib/sinatra/base.rb:1533:in `block in compile!': undefined method `consumes' for VCAP::CloudController::Controller:Class (NoMethodError)
	from /var/vcap/packages/cloud_controller_ng/cloud_controller_ng/vendor/bundle/ruby/1.9.1/gems/sinatra-1.4.3/lib/sinatra/base.rb:1533:in `each_pair'
	from /var/vcap/packages/cloud_controller_ng/cloud_controller_ng/vendor/bundle/ruby/1.9.1/gems/sinatra-1.4.3/lib/sinatra/base.rb:1533:in `compile!'
	from /var/vcap/packages/cloud_controller_ng/cloud_controller_ng/vendor/bundle/ruby/1.9.1/gems/sinatra-contrib-1.4.0/lib/sinatra/reloader.rb:253:in `compile!'
	from /var/vcap/packages/cloud_controller_ng/cloud_controller_ng/vendor/bundle/ruby/1.9.1/gems/sinatra-1.4.3/lib/sinatra/base.rb:1515:in `route'
	from /var/vcap/packages/cloud_controller_ng/cloud_controller_ng/vendor/bundle/ruby/1.9.1/gems/sinatra-1.4.3/lib/sinatra/base.rb:1352:in `post'
```