Update README.md

Fixing tests that broke thanks to new dependencies.

Requiring formatters fixes #30.

Changing the name of the package to league/booboo for packagist.

Updating the changelog for 0.4.2

Moving Raven to a dev dependency, since I need it but others might no…

…t want it.

Fixing the tests to reflect new error messaging.

Fixing a bug where the line was not passed on a fatal error. Disablin…

…g built-in error display on construct. Update tests.

Adding a shutdown handler to deal with fatal error conditions.

Adding a changelog.