Rename "matrix" to "jobs" in Travis config
Rename "matrix" to "jobs" in Travis config

Travis says "key matrix is an alias for jobs, using jobs"

RJPercival/certificate-transparency-go,daviddrysdale/certificate-transparency-go,daviddrysdale/certificate-transparency-go,google/certificate-transparency-go,daviddrysdale/certificate-transparency-go,google/certificate-transparency-go,RJPercival/certificate-transparency-go,RJPercival/certificate-transparency-go,google/certificate-transparency-go