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
support doubleclick to display advertising

using doubleclick.net script instead of google-analytics.

see it: https://support.google.com/analytics/answer/2444872?hl=en&utm_id=ad

Usage:

use Rack::GoogleAnalytics, :tracker => 'UA-xxxxx-x', :advertising => true
fast forward to support the new analytics.js. custom variables are discontinued and will revive as custom dimensions and metrics
setting custom tracker options. cookieDomain as the first
update gemspec
run tests also on analytics branch
include travis badge in readme [ci skip]
travis build status
Merge pull request #27 from masarakki/enable_doubleclick

support doubleclick to display advertising
fix tests. i wonder if checking for the content length is so useful ;)
allow tracking of events only
add pry-debugger to the Gemfile and test helper for comfortable debugging
fix tests
described events_only in the README and CHANGELOG
Merge pull request #29 from kangguru/events_only

Allow tracking of events only
added to support inpage pageid plugin.
fix order of _gaq.push
added default value