GH-31: Add no-op ember-i18n initializer

The removal of the ember-i18n initializer had unseen consequences for
applications that were injecting the i18n service into other areas of
the application, as recommended by documentation in the project's wiki
(https://github.com/jamesarosen/ember-i18n/wiki/Doc:-i18n-Service).

As per the discussion in GH-31 this adds a no-op initializer back into
the code base to prevent breaks for applications injecting the i18n
service as per the wiki.

addon/initializers/ember-i18n.js

@@ -0,0 +1,9 @@
+import Ember from "ember";
+
+export default {
+  name: 'ember-i18n',
+
+  initialize(registry) {
+    // No-op.
+  }
+};

app/initializers/ember-i18n.js

@@ -0,0 +1,2 @@
+import initializer from 'ember-i18n/initializers/ember-i18n';
+export default initializer;