client: drop deadline-fiddling from tests
client: drop deadline-fiddling from tests

Aim to reduce Travis test flakes
daviddrysdale/trillian,RJPercival/trillian,Martin2112/trillian,Martin2112/trillian,AlCutter/trillian,codingllama/trillian,daviddrysdale/trillian,gdbelvin/trillian,gtank/trillian,google/trillian,daviddrysdale/trillian,AlCutter/trillian,codingllama/trillian,gdbelvin/trillian,RJPercival/trillian,Martin2112/trillian,gtank/trillian,google/trillian,gdbelvin/trillian