Added support for Closeable in MySqlConnectionFactory

[svats0001]

Hi @jchrys,

#66

I added support for the Closeable interface in MySqlConnectionFactory and I also removed the invocation of the deprecated getSocketTimeout() and replaced it with null in MySqlConnectionFactory. Let me know if there are any problems in the code.

Motivation: MySqlConnectionFactory could benefit from a way to release its resources through implementing the Closeable interface.

Modification: MySqlConnectionFactory now implements Closeable and contains the close() method that will close the underlying MySqlConnection resource. I also added a logger to add the close start/end progress to the log. I removed the configuration.getSocketTimeout() parameter from Client.connect in the from() method and replaced it with null.

Result: MySqlConnectionFactory now has a way for users to release its resources.

[jchrys]

hello, @svats0001.
I think it seems that it creates a new connection and returns close Mono. (it doesn't seem to affect the factory)

[svats0001]

Oh I see. I'm not too sure what's required to close the ConnectionFactory. I'll try again later. Closing the PR.