Merge pull request #22 from kangguru/master

Adding support for generic pushes into the async queue
`trackPageLoadTime` is deprecated this closes #10
adding bundler gem tasks
preparing 0.12.0 release
adding `domain` option to the readme
adding a license closing #23
adding travis
removed duplicated version file
Make test run
Avoid error on redirection when "rack.session" is nil

- NoMethodError: undefined method `[]=' for nil:NilClass
Merge pull request #26 from thibaudgg/without_rack_session

Avoid error on redirection when "rack.session" is nil