Add current execution context in hook

[apoorvam]

To get additional information about the current specification, scenario and step executing, an additional ExecutionContext parameter can be added to the hooks method.

More details on this feature: http://getgauge.io/documentation/user/current/advanced_readings/execution_hooks/context.html

[emlaver]

+1 it would be great to have access to the context object which would be in-line with the Node, Python, Java, and possibly other language implementations.

Updated documentation link: https://docs.gauge.org/writing-specifications.html?os=macos&language=golang#current-execution-context-in-the-hook