ensure-up-to-date - add r and javascript

[karismann]

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, ./bin/openapi3/{LANG}-petstore.sh, ./bin/security/{LANG}-petstore.sh and ./bin/openapi3/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.

Description of the PR

Add R and JavaScript in ensure-up-to-date sample scripts

for #80

[wing328]

@karismann thanks for the PR. We can definitely include these.

(FYI. The R integration tests are run via https://github.com/wing328/petstore-r-client instead.