Added 'Key AppEvent Properties' section to README.md 

Merge pull request #14 from trakerr-com/develop API v3 features.

Minor README.md formatting 

Update README.md Fixed EnvLanguange in the readme table.

Refactor 2 finish. (#9) Loglevel added, classification changed to optional, swagger code fixes to eventspost/async with reponse to populate data with server message. Added EnvLanguage and deployment stage property, name now becomes the runtime interpreter name and envVersion now works as intended.