[BUG] php-slim4-server tests are failing in CI

Created by: spacether

Bug Report Checklist

Have you provided a full/minimal spec to reproduce the issue?
Have you validated the input using an OpenAPI validator (example)?
What's the version of OpenAPI Generator used?
Have you search for related issues/PRs?
What's the actual output vs expected output?
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Description

php-slim4-server tests are failing in CI An example of it is here: https://travis-ci.org/OpenAPITools/openapi-generator/builds/636572707?utm_source=github_status&utm_medium=notification

Suggest a fix

It looks like we need to change the version of the slim-token-authentication library that we are using