chore(package): update zone.js to version 0.6.6
chore(package): update zone.js to version 0.6.6

http://greenkeeper.io/
javlaking/testangular2ci,tsungting/blue-bird,e-schultz/angular2-redux-example,javlaking/testangular2ci,rangle/angular2-redux-starter,rangle/angular2-redux-starter,lokeshjain2008/ng2practice,javlaking/testangular2ci,rangle/ng2-redux-starter,tsungting/blue-bird,tsungting/blue-bird,e-schultz/angular2-redux-example,stevenkampen/ng2-sequencer,lokeshjain2008/ng2practice,rangle/angular2-redux-starter,rangle/ng2-redux-starter,lokeshjain2008/ng2practice,tsungting/blue-bird,rangle/angular2-redux-starter,stevenkampen/ng2-sequencer,rangle/angular2-redux-starter,stevenkampen/ng2-sequencer,javlaking/testangular2ci,rangle/ng2-redux-starter,tsungting/blue-bird,javlaking/testangular2ci,e-schultz/angular2-redux-example