devel/ruby-byebug: update to 11.1.0

Update ruby-byebug to 11.1.0.

## [11.1.0] - 2020-01-20

### Added

* Official support for MRI 2.7 ([@yui-knk]).

### Fixed

* [#562](https://github.com/deivid-rodriguez/byebug/pull/562): post mortem mode landing in the wrong line when coming from an exception inside a `Kernel.load` call.

### Removed

* Support for MRI 2.3. Byebug no longer installs on this platform.

(taca)