[gssapi/gssproxy] e2240d: Update EXTRA_DIST for missing test files

[Robbie Harwood]

Branch: refs/heads/main
  Home:   https://github.com/gssapi/gssproxy
  Commit: e2240d1b8f1d68fdfbf0881ad892d9b1956e4512
      https://github.com/gssapi/gssproxy/commit/e2240d1b8f1d68fdfbf0881ad892d9b195...
  Author: Robbie Harwood 
  Date:   2020-10-30 (Fri, 30 Oct 2020)

Changed paths:
    M tests/Makefile.am

Log Message:
  -----------
  Update EXTRA_DIST for missing test files

- t_names.py was added in 27bf21cc119005e0e6d9f1d58592408b5cd6337c
- t_program.py was added in f61449b0212170d1dd619738e243e8f409ea161c
- t_setcredopt.py was added in 8572a84778e1bae74fbc396d4b9922b490ee2837

Signed-off-by: Robbie Harwood