Add Azure Application Insights Provider

[TheLarkInn]

Hey @sindresorhus @addyosmani and all the other great folks maintaining this org!

Was wondering if ya'll would take a PR for adding a new provider aside from GA/Yandex? It looks like the API is pretty harmless already.

There is already a pretty good library for Azure App Insights (https://github.com/Microsoft/ApplicationInsights-node.js) however it doesn't have some of the more eloquent permission, TTA, and cache control that Insight has! (And is kind of overkill for a lightweight reporter like insight which is what we are really looking for [to use with webpack]).

[sindresorhus]

Sure, if someone can commit to maintaining it. I don't have time to maintain more code here.

[TheLarkInn]

Fair enough! <3, looking to keep it as lightweight as possible Thx.