feat(decorator): Add decorator templates

Added generator for service decorator.


Description:
    Creates a new AngularJS decorator for a specified service

Example:
    yo angular:decorator serviceName [--coffee]

    This will create:
        app/scripts/decorators/serviceNameDecorator.js


    If you want to use multiple decorators for one service,
    you are able to use the second argument for the filename

    yo angular:decorator serviceName serviceNameLogging [--coffee]

    This will create:
            app/scripts/decorators/serviceNameLoggingDecorator.js