fix: avoid requirements to jdk.unsupported module

[bednar]

Closes #256

Proposed Changes

1. Avoid requirements to jdk.unsupported module. workaround: --add-modules jdk.unsupported
2. Update GSON to 2.8.8:
   

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• A test has been added if appropriate
• mvn test completes successfully
• Commit messages are in semantic format
• Sign CLA (if not already signed)

[codecov-commenter]

Codecov Report

Merging #258 (f975a0c) into master (050db6a) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #258   +/-   ##
=========================================
  Coverage     89.17%   89.17%           
  Complexity      449      449           
=========================================
  Files           145      145           
  Lines          5773     5773           
  Branches        272      272           
=========================================
  Hits           5148     5148           
  Misses          545      545           
  Partials         80       80           

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