Merge pull request #12 from AaronO/master

Set Content-Type to application/json when posting JSON
added build badge
changed ci badge
fixed typo
added more badges
updated reps
upgraded the default API version to 1.5 and fixed some tests
Fixed a MAJOR bug that caused the wrong callback to be called at times
fixed build badge url
Update README.md
Update README.md
I HATE how github caches freaking http images
Add /events endpoint