submission: defer loading of test certificates (#474)
submission: defer loading of test certificates (#474)

Only load test certificates after tests have started, to allow
the tests to run in some environments where CWD isn't initially
set.
RJPercival/certificate-transparency-go,google/certificate-transparency-go,daviddrysdale/certificate-transparency-go,google/certificate-transparency-go,RJPercival/certificate-transparency-go,daviddrysdale/certificate-transparency-go,daviddrysdale/certificate-transparency-go,RJPercival/certificate-transparency-go,google/certificate-transparency-go