[plugin request] Azure Application Insights output

It would be very nice to have an [Application Insights](azure.microsoft.com/en-us/services/application-insights/) plugin. That would allow people who run their service on Microsoft Azure to send their traces directly to Application Insights, not care about the storage or anything else, and leverage AI right away.

Microsoft is providing a [Ruby SDK](https://github.com/Microsoft/ApplicationInsights-Ruby), which should make everything easier.