Add a global timeout parameter to Connection

[gschneider-r7]

It should be possible to set a global timeout used by all requests when setting up the Connection object. Currently only a few specific methods support a non-default timeout value as input. For everything else the only other option is to monkey patch the APIRequest and AJAX classes to override their HTTP module setup (example). The monkey patching method is not ideal because it is extra code to copy/paste into new scripts or applications, and also because it can break when upgrading the gem. For example when we added the trusted certificate feature, anyone using the monkey patch would get non-sensical errors until they updated their monkey patch.

[sgreen-r7]

Closing: https://github.com/rapid7/nexpose-client/releases/tag/v7.0.0