55: bind a Rollbar exception handler to report exceptions to rollbar

Dropping HHVM as PHPUnit is dropping support"

HHVM failures allowed

Merge branch 'release/3.0.2'

addressing code formatting issue

namespacing package

Update the build badge url

Merge pull request rollbar#26 from paulrrogers/laravel-v5-5-workaround

Fix Laravel 5.5 missing traces by shifting exception back into 'message'

Merge pull request rollbar#18 from mbardelmeijer/patch-1

Check the correct token to ensure if we need to register

Merge pull request rollbar#17 from drbyte/patch-1

Update README.md for clarity