Replace --without option with config set command on bundle install

bundle install --with was deprecated in favor of bundle config set.

Signed-off-by: Takuya Noguchi <[email protected]>

Author: tnir

guides/source/development_dependencies_install.md

@@ -229,7 +229,8 @@ $ bundle install
 If you don't need to run Active Record tests, you can run:
 
 ```bash
-$ bundle install --without db
+$ bundle config set without db
+$ bundle install
 ```
 
 ### Contribute to Rails