v2.2.0

Improvements:

• bump dep to libhoney to ^2.2.1 (#234) @toshok
  (adds console transmission option, enforce response queue limits)
• common http request headers added to auto-instrumented fields (#206) @paulosman
• support for 3-arg http/s .get/.request (node-10.0.9) (#213) @toshok
• null guard to addContext mock implementation (#215) @kenmclennan
• trace ids and span ids conform to w3c spec (#216) @katiebayes
• response context in http/s (#223) @loganrdavis-ns8

Some fixes:

• fix use of function for parentIdSource (#205) @mikesimons
• fix multi-prefixing of .app behavior on custom fields (#226) @katiebayes

One inadvertent breaking change:

• libhoney@2.2.1 includes a change to the format of events sent to transmissions. This may cause problems if you're writing a custom Transmission implementation, or if you have been writing tests that look at event postData. postData was a string (from JSON.stringify) and is now the object.

If you wrote tests that use the mock transmission and check event payloads, you will no doubt have code that does, essentially:

const eventData = JSON.parse(...event.postData);

This will need to change to:

const eventData = ...event.postData;