travis: remove Release builds as they are the same as RelWithDebInfo optimization-wise
travis: remove Release builds as they are the same as RelWithDebInfo optimization-wise

offa/Criterion,am11/Criterion,a1lu/Criterion,a1lu/Criterion,Snaipe/Criterion,offa/Criterion,offa/Criterion,am11/Criterion,Snaipe/Criterion,Snaipe/Criterion,am11/Criterion,am11/Criterion,offa/Criterion,Snaipe/Criterion,Snaipe/Criterion,offa/Criterion,am11/Criterion,a1lu/Criterion,a1lu/Criterion,a1lu/Criterion