Fix improper brace-initialization in unit test. (#437)
Fix improper brace-initialization in unit test. (#437)

* Replace improper use of brace initialization of vectors of classes with a deleted move constructed with a sequence of `emplace_back` invocations.
halfflat/arbor,eth-cscs/nestmc-proto,halfflat/arbor,halfflat/arbor,eth-cscs/nestmc-proto,halfflat/arbor,halfflat/arbor,halfflat/nestmc-proto,halfflat/nestmc-proto,halfflat/nestmc-proto,eth-cscs/nestmc-proto