Breaking changes
These are all the breaking changes – that is changes that you absolutely have to worry about if you are updating your app from 1.2.x to 1.3. However, we recommend that you also consider the recommended changes listed in the other sections below.
Files in a directory named imports/ will no longer load eagerly. (You should probably rename such a directory as it the basis of our new module system).
Files within your app named *.test[s].*, *.app-test[s].*, *.spec[s].* and *.app-