Fix security vulnerabilities

[coreagile]

While evaluating this library for use in my project, I discovered several security vulnerabilities in its dependencies:

retrofit-2.1.0.jar: CVE-2018-1000850 jsoup-1.10.3.jar: CVE-2021-37714 gson-2.8.2.jar: CVE-2022-25647 httpclient-4.2.3.jar: CVE-2014-3577

This fixes these.