Explicitly set the locmem email backend for tests to avoid cases where it somehow fails to be set correctly in tests (review by @justinvdm).
Explicitly set the locmem email backend for tests to avoid cases where it somehow fails to be set correctly in tests (review by @justinvdm).

praekelt/vumi-go,praekelt/vumi-go,praekelt/vumi-go,praekelt/vumi-go