Delete TestResultsServer

This code now lives in infra/appengine/test_results
as of https://codereview.chromium.org/488853003/

BUG=405385
TBR=ojan@chromium.org

Review URL: https://codereview.chromium.org/464163006

git-svn-id: svn://svn.chromium.org/blink/trunk@180628 bbb929c8-8fbe-4397-9dbb-9b2b20218538