t_auth memory checks

[swlars]

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• Version of iperf3 (or development branch, such as master or
  3.1-STABLE) to which this pull request applies:

• Issues fixed (if any):

Fix memory leaks in t_auth checks, and add make check to github actions

• Brief description of code changes (suitable for use as a commit message):

[bmah888]

Seems right to me. Approved!