Setting for operation timeout

Problem/Motivation

The module has a setting for connection timeout connect_timeout, but not operational timeout (timeout). Without this setting, Guzzle will default to attempting the query until the web server timesout, resulting in the page not being displayed. A better outcome would be to fail to retrieve trustpilot results quickly, allowing the page to be rendered without trustpilot results as opposed to not being rendered at all.

User interface changes

Add a setting for "Timeout" on the settings page, default to 15 seconds.