Revert "- Activate `diagnostics.all_errors_are_fatal` on non-MRI Rubies as a workaround (closes #93)."
Revert "- Activate `diagnostics.all_errors_are_fatal` on non-MRI Rubies as a workaround (closes #93)."

This reverts commit eafee9de93fa79ec4ec239867437dd5b39c46da6.

bbatsov/parser