Add Facebook in-app browser

Meteor projects depending on Firebase (such as implementations of Push Notifications) do not run in Facebook in-app browser due to an error: "Uncaught TypeError: Y.values is not a function or its return value is not iterable."  Adding FB in-app browser to this default list fixes the issue.

npm-packages/babel-preset-meteor/babel-presets-meteor/modern.js

@@ -26,5 +26,6 @@ exports.minimumVersions = {
   // https://github.com/Kilian/electron-to-chromium/blob/master/full-versions.js
   electron: [1, 6],
   // https://github.com/meteor/babel-preset-meteor/issues/13
-  samsungInternet: [6, 2]
+  samsungInternet: [6, 2],
+  facebook: 325
 };