Bump s3 plugin to 0.4.0

Author: lukemelia

package.json

@@ -22,7 +22,7 @@
     "ember-cli-deploy-display-revisions": "0.2.2",
     "ember-cli-deploy-gzip": "0.2.3",
     "ember-cli-deploy-redis": "0.4.1",
-    "ember-cli-deploy-s3": "0.3.1",
+    "ember-cli-deploy-s3": "0.4.0",
     "ember-cli-deploy-manifest": "0.1.1",
     "ember-cli-deploy-revision-data": "0.3.2"
   },