[Fix #210] Change enforced style to conditionals for Style/AndOr

Resolves #210.

The following idioms exist for `return` and` raise` in Ruby.

- `do_something and return`
- `do_something || raise`

And Rails will also show users the error message using this idiom.

> `"redirect_to(...) and return\"`

https://github.com/rails/rails/blob/v6.0.2.2/actionpack/lib/abstract_controller/rendering.rb#L10

This is the same for `render :action and return` and others.

`Style/AndOr` cop default rule (`EnforcedStyle: always`) does seem to
unmatch for these cases. I think these cases need to be accepted.

So, this PR changes it to `EnforcedStyle: conditionals` at least in Rails.
The enforced style cannot catch all cases, but probably the closest to
solving the issue.

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## master (unreleased)
 
+### Changes
+
+* [#210](https://github.com/rubocop-hq/rubocop-rails/issues/210): Accept `redirecto_to(...) and return` and similar cases. ([@koic][])
+
 ## 2.5.1 (2020-04-02)
 
 ### Bug fixes

config/default.yml

@@ -543,3 +543,7 @@ Rails/Validation:
   VersionChanged: '0.41'
   Include:
     - app/models/**/*.rb
+
+# Accept `redirecto_to(...) and return` and similar cases.
+Style/AndOr:
+  EnforcedStyle: conditionals