Update to ember 2.8.0 and ember-engines 0.3.0

Project Update

$ ember install telling-stories

$ npm install --save-dev telling-stories@v1.0.0-alpha.3
$ ember generate telling-stories

Community contributions

• #17 Update ember (@san650)
• #15 Look for elements inside the container (@san650)
• #18 Set default container (@san650)