require 'oj' is not necessary in base-event-manager.rb

[tune]

It seems 'oj' is not mandatory for this gem.

[dariocravero]

Hey @tune, thanks for your message. However, it's being used in on_message and then inside each of the application server implementations to write to the WS. :)

[tune]

If so, I think it's better to add dependency information to 'padrino-websockets.gemspec'.

[dariocravero]

👍 sorry I totally missed that! :/