Remove unnecessary loading of public key from signer_test.go
Remove unnecessary loading of public key from signer_test.go

RJPercival/trillian,google/trillian,codingllama/trillian,RJPercival/trillian,AlCutter/trillian,gdbelvin/trillian,gdbelvin/trillian,Martin2112/trillian,Martin2112/trillian,daviddrysdale/trillian,daviddrysdale/trillian,codingllama/trillian,gdbelvin/trillian,AlCutter/trillian,daviddrysdale/trillian,google/trillian,Martin2112/trillian