Fix return_type parameter examples in ruby-client

[meganemura]

PR checklist

• Read the contribution guidelines.
• Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh and ./bin/security/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\.
• Filed the PR against the correct branch: master, 3.4.x, 4.0.x. Default: master.
• Copied the technical committee to review the pull request if your PR is targeting a particular programming language.

Description of the PR

Fix the wrong examples of return_type.
We need <> brackets for parsing return_type.
See:

openapi-generator/modules/openapi-generator/src/main/resources/ruby-client/api_client.mustache

Lines 195 to 204 in 3494542

	when /\AArray<(.+)>\z/
	# e.g. Array<Pet>
	sub_type = $1
	data.map { |item| convert_to_type(item, sub_type) }
	when /\AHash\<String, (.+)\>\z/
	# e.g. Hash<String, Integer>
	sub_type = $1
	{}.tap do |hash|
	data.each { |k, v| hash[k] = convert_to_type(v, sub_type) }
	end

[wing328]

@meganemura thanks for the PR. Can you please run ./bin/ruby-petstore.sh or bin\windows\ruby-petstore.bat to update the Petstore samples so that CI can verify the change?

[meganemura]

@wing328

./bin/ruby-petstore.sh produces many diffs 😩

In bin/utils/ensure-up-to-date, we runs bin/openapi3/ruby-client-petstore.sh to check whether the sample is up-to-date or not.
So I use bin/openapi3/ruby-client-petstore.sh to build sample client and commit it.

By the way, do we need ./bin/ruby-petstore.sh? If not, I will remove it.

[meganemura]

I think we need to update some java samples since the build of master branch is broken.

https://circleci.com/gh/OpenAPITools/openapi-generator/3274#tests/containers/2

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

	modified:   samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/JSON.java
	modified:   samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/JSON.java
	modified:   samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/JSON.java
	modified:   samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/JSON.java
	modified:   samples/client/petstore/java/retrofit2rx/src/main/java/org/openapitools/client/JSON.java
	modified:   samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/JSON.java

no changes added to commit (use "git add" and/or "git commit -a")
Please run 'bin/utils/ensure-up-to-date' locally and commit changes (UNCOMMITTED CHANGES ERROR)
Exited with code 1

[wing328]

@meganemura right. I've fixed the issue in master via #1405. Thanks again for your contribution 👍

[wing328]

@meganemura thanks again for the PR, which has been included in the v3.3.3 release: https://twitter.com/oas_generator/status/1062929948191510528