Add a fix for RN hang with promises

lib/extensions.js

@@ -50,7 +50,7 @@ module.exports = function(realmConstructor) {
                     }
 
                     let syncedRealm = new realmConstructor(config);
-                    resolve(syncedRealm);
+                    setTimeout(_ => { resolve(syncedRealm); }, 1); //FIXME: RN hangs here. Remove when node's makeCallback alternative is implemented                    
                 });
             });
         },
@@ -64,7 +64,6 @@ module.exports = function(realmConstructor) {
                     let syncedRealm = new realmConstructor(config);
                     callback(null, syncedRealm);
                 });
-
         },
     }));