Added `chalk` to dev dependencies.
Added `chalk` to dev dependencies.

Fixes rangle/rangle-starter#30

tsungting/blue-bird,javlaking/testangular2ci,rangle/ng2-redux-starter,javlaking/testangular2ci,timathon/sgz,rangle/angular2-redux-starter,tsungting/blue-bird,rangle/angular2-redux-starter,stevenkampen/ng2-sequencer,rangle/angular2-redux-starter,rangle/ng2-redux-starter,lokeshjain2008/ng2practice,e-schultz/angular2-redux-example,tsungting/blue-bird,lokeshjain2008/ng2practice,rangle/angular2-redux-starter,e-schultz/angular2-redux-example,stevenkampen/ng2-sequencer,javlaking/testangular2ci,tsungting/blue-bird,timathon/sgz,rangle/angular2-redux-starter,javlaking/testangular2ci,rangle/ng2-redux-starter,tsungting/blue-bird,timathon/sgz,stevenkampen/ng2-sequencer,e-schultz/angular2-redux-example,lokeshjain2008/ng2practice,javlaking/testangular2ci