Allow passing in ActiveRecord::Relation to send_message and reply

Currently if you pass in an ActiveRecord::Relation you get an error like the following:

```ruby
undefined method `primary_key' for User::ActiveRecord_Relation:Class
```

That's because this Relation gets stuffed into an array when recipients are assigned since this is not an array. To overcome this, we can use the `Array.wrap` method to always make sure recipients is an array.

Now you can just simply query for records and pass them in as recipients:

```ruby
users = User.all
current_user.send_message(users, "Hey guys", "Hello")
```