Implements a connection pool.

[sturzael]

You aren't supposed to open and close the connection each time you make a new request.

This way, new connections can use the existing pool rather than having to wait for the previous one to be closed.

Don't repeatedly use connect() & end() as this will eventually cause issues. Just open it once and reuse it.

[sturzael]

bump

[nax3t]

@sturzael I'm getting an error for connection.destroy() with your implementation: TypeError: connection.destroy is not a function