Ensure that even with non-string logger, error gets sent to sentry
added string interpolation and README changes
edited the readme to reflect the new error API
Changed error API
added test to deal with optional culprit. changed other tests to reflect change in argument order to error
had an it.only in tests.
culprit is not optional - if you don't want it must put null
Fixed lint errors
added stack trace to extra in 1 line, not 2
changed error messages
Merge pull request #14 from Clever/change-error-function

Change error function
Merge pull request #13 from Clever/ensure-errors-reach-sentry2

Ensure errors reach sentry