Perform upgrade to use the socket.io@latest

[mechamogeo]

Today, i need to use socket.io@2.4.1 in npm to can use this lib.
Because the EngineIO used is the engine 3 and the newer version requires the EngineIO 5.

If upgrades, i will not receive error 404 Unsupported version anymore.

[ghmendonca]

I will work on updating socket io this weekend and publish a new version

[mechamogeo]

Thank you so much, this lib is very very very useful for my projects