Enabling logSpans flag causes exception

[yurishkuro]

The logging reporter writes the span with JSON.stringify, which fails because of some recursive links in the span.

Instead, it should log the span in the same format as other clients, as trace context + operation name.

[rajeshsegu]

Is there a reason why we are not using just util.inspect since this is a node only framework

util.inspect(span, {depth: 3});

Happy to send a pull request, if you like the solution.

[yurishkuro]

I don't see the need for logging any details of the span itself. For example, in Go client the log looks like this

2017/09/22 20:26:49 Reporting span 5642914c078ef2f0:5642914c078ef2f0:0:1