Update node version and remove workarounds for older versions

bbb-webhooks/application.js

bbb-webhooks/callback_emitter.js

bbb-webhooks/config.js

bbb-webhooks/config_local.js.example

bbb-webhooks/hook.js

bbb-webhooks/id_mapping.js

bbb-webhooks/logger.js

bbb-webhooks/messageMapping.js

bbb-webhooks/package.json

bbb-webhooks/utils.js

bbb-webhooks/web_hooks.js

bbb-webhooks/web_server.js