Add dierksen to CONTRIBUTORS.
Add dierksen to CONTRIBUTORS.

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PiperOrigin-RevId: 180729252
MOS_MIGRATED_REVID=180729252

bazelbuild/tulsi,pinterest/tulsi,pinterest/tulsi,bazelbuild/tulsi,bazelbuild/tulsi,bazelbuild/tulsi,pinterest/tulsi,bazelbuild/tulsi,pinterest/tulsi,pinterest/tulsi,pinterest/tulsi,bazelbuild/tulsi