Add support for mutli-line return text (thx @yous)

Fixes inch-ci/inch_ci-web#23
Set version to 0.4.7 for release

Skip some tests describing features for 0.5
Regenerate .rubocop_todo.yml
Remove useless assignment
Use safe assignment in condition
Avoid prefixing reader method name with `get_`
Remove `self.Filter` and `self.Suggest`

Replace them with `Filter.new` and `Suggest.new` respectively.
Use `attr_reader` to define trivial reader methods
Use `_` prefix in unused argument name
Avoid using prefix `_` for a used variable
Keep line length to 80
Merge pull request #23 from yous/patch-rubocop

Reduce RuboCop offenses
Update CHANGELOG
Rename special global var to english version
Fix error in Rake task (thanks @tabolario)

Inch::CLI needs to be required manually (see CHANGELOG for 0.4.7).

Fixes #24
Bump version to 0.4.8
Update CHANGELOG
Revert 78a5c10af39b03d5
Bump version to 0.4.9
Handle unusable return values

This patch handles cases like this:

  # Does something.
  # @return [void]
  def foo
  end

where the docs indicate that a return value is not intended for further
use. After this patch, Inch won't suggest "Describe what foo returns."
anymore.