chore(package): update ember-source to version 3.0.0-beta.4
chore(package): update ember-source to version 3.0.0-beta.4

Closes #640
mike-north/ember-cli-materialize,truenorth/ember-cli-materialize,rynam0/ember-cli-materialize,rynam0/ember-cli-materialize,truenorth/ember-cli-materialize,mike-north/ember-cli-materialize,mike-north/ember-cli-materialize,rynam0/ember-cli-materialize,truenorth/ember-cli-materialize,sgasser/ember-cli-materialize,sgasser/ember-cli-materialize,sgasser/ember-cli-materialize