[BUGFIX lts] Check length of targets
[BUGFIX lts] Check length of targets

We had a bug where if you had additional targets added, they would not be checked, we were just checking that all the prebuilt targets were included. This adds a check for length to ensure all the targets are there and no additional ones are.

GavinJoyce/ember.js,givanse/ember.js,emberjs/ember.js,fpauser/ember.js,elwayman02/ember.js,stefanpenner/ember.js,stefanpenner/ember.js,givanse/ember.js,miguelcobain/ember.js,knownasilya/ember.js,tildeio/ember.js,fpauser/ember.js,sandstrom/ember.js,miguelcobain/ember.js,asakusuma/ember.js,tildeio/ember.js,givanse/ember.js,mfeckie/ember.js,miguelcobain/ember.js,fpauser/ember.js,GavinJoyce/ember.js,mfeckie/ember.js,knownasilya/ember.js,sly7-7/ember.js,stefanpenner/ember.js,mfeckie/ember.js,asakusuma/ember.js,GavinJoyce/ember.js,miguelcobain/ember.js,mixonic/ember.js,sly7-7/ember.js,mixonic/ember.js,sandstrom/ember.js,intercom/ember.js,GavinJoyce/ember.js,elwayman02/ember.js,knownasilya/ember.js,sly7-7/ember.js,intercom/ember.js,mixonic/ember.js,emberjs/ember.js,fpauser/ember.js,elwayman02/ember.js,givanse/ember.js,elwayman02/ember.js,intercom/ember.js,mfeckie/ember.js,emberjs/ember.js,asakusuma/ember.js,tildeio/ember.js,asakusuma/ember.js,sandstrom/ember.js,intercom/ember.js