docs: Fix required ruby-version (#675)

* fix required ruby-version

Signed-off-by: mkontani <itoama@live.jp>

* add a changelog entry

Signed-off-by: mkontani <itoama@live.jp>

Co-authored-by: Joel Speed <Joel.speed@hotmail.co.uk>

CHANGELOG.md

@@ -8,6 +8,7 @@
 
 ## Changes since v6.0.0
 
+- [#675](https://github.com/oauth2-proxy/oauth2-proxy/pull/675) Fix required ruby version and deprecated option for building docs (@mkontani)
 - [#669](https://github.com/oauth2-proxy/oauth2-proxy/pull/669) Reduce docker context to improve build times (@JoelSpeed)
 - [#668](https://github.com/oauth2-proxy/oauth2-proxy/pull/668) Use req.Host in --force-https when req.URL.Host is empty (@zucaritask)
 - [#660](https://github.com/oauth2-proxy/oauth2-proxy/pull/660) Use builder pattern to simplify requests to external endpoints (@JoelSpeed)

docs/Makefile

@@ -1,7 +1,7 @@
 .PHONY: ruby
 ruby:
 	@ if [ ! $$(which ruby) ]; then \
-			echo "Please install ruby version 2.1.0 or higher"; \
+			echo "Please install ruby version 2.5.0 or higher"; \
 		fi
 
 .PHONY: bundle
@@ -11,7 +11,8 @@ bundle: ruby
 		fi
 
 vendor/bundle: bundle
-	bundle install --path vendor/bundle
+	bundle config set --local path 'vendor/bundle'
+	bundle install
 
 .PHONY: serve
 serve: vendor/bundle

docs/README.md

@@ -9,5 +9,5 @@ When making changes to this docs site, please test your changes locally:
 docs$ make serve
 ```
 
-To run the docs site locally you will need Ruby at version 2.1.0 or
+To run the docs site locally you will need Ruby at version 2.5.0 or
 higher and `bundle` (`gem install bundler` if you already have Ruby).