This should fix the "gem install danger-gitlab" command, which was
returning:

ERROR:  Error installing danger-gitlab:
	There are no versions of octokit (~> 5.0) compatible with your Ruby & RubyGems. Maybe try installing an older version of the gem you're looking for?
	octokit requires Ruby version >= 2.7.0. The current ruby version is 2.5.9.229.

Docker image has an outdated ruby version

Feature/appcircle support

Several typos were corrected in this PR.

Fix a few typos #trivial

The following error occurred when currently running the RuboCop, so this PR is fixed this error.

```
bundle exec rubocop
.rubocop.yml: Metrics/LineLength has the wrong namespace - should be Layout
.rubocop.yml: Style/FileName has the wrong namespace - should be Naming
/Users/yudai.takada/ydah/danger/.rubocop.yml: Warning: no department given for PercentLiteralDelimiters.
Error: The `Layout/AlignHash` cop has been renamed to `Layout/HashAlignment`.
(obsolete configuration found in .rubocop.yml, please update it)
The `Layout/IndentHash` cop has been renamed to `Layout/FirstHashElementIndentation`.
(obsolete configuration found in .rubocop.yml, please update it)
The `Layout/IndentHeredoc` cop has been renamed to `Layout/HeredocIndentation`.
(obsolete configuration found in .rubocop.yml, please update it)
The `Style/BracesAroundHashParameters` cop has been removed.
(obsolete configuration found in .rubocop.yml, please update it)
```

Fix RuboCop runtime errors #trivial

The following warnings occurred when currently running the RuboCop, so this PR is fixed this warnings.

```
/ydah/danger/lib/danger/danger_core/dangerfile.rb: Warning: no department given for Eval. Run `rubocop -a --only Migration/DepartmentName` to fix.
spec/lib/danger/helpers/comments_helper_spec.rb: Metrics/LineLength has the wrong namespace - should be Layout
spec/lib/danger/helpers/comments_helper_spec.rb: Metrics/LineLength has the wrong namespace - should be Layout
spec/lib/danger/helpers/comments_helper_spec.rb: Metrics/LineLength has the wrong namespace - should be Layout
spec/lib/danger/helpers/comments_helper_spec.rb: Metrics/LineLength has the wrong namespace - should be Layout
spec/lib/danger/helpers/comments_helper_spec.rb: Metrics/LineLength has the wrong namespace - should be Layout
spec/lib/danger/helpers/comments_helper_spec.rb: Metrics/LineLength has the wrong namespace - should be Layout
spec/lib/danger/helpers/comments_helper_spec.rb: Metrics/LineLength has the wrong namespace - should be Layout
spec/lib/danger/helpers/comments_helper_spec.rb: Metrics/LineLength has the wrong namespace - should be Layout
.rubocop.yml: Metrics/LineLength has the wrong namespace - should be Layout
.rubocop.yml: Style/FileName has the wrong namespace - should be Naming
/ydah/danger/.rubocop.yml: Warning: no department given for PercentLiteralDelimiters.
```

Appcircle Support

Fix RuboCop runtime warnings #trivial