Convergence test: Double white dwarf merger (Octo-Tiger)

Configuration files to reproduce the simulation for the convergence test. To generate the input files run: octotiger --config_file=rcb_init.init --silo_num_groups=n Octo-Tiger (b4c51431) and following dependencies were used HPX (1.4.0), hwloc (1.11.1), silo (4.10.2), jemalloc (5.1.0), hdf5 (1.8.12), cray-mpich/MVAPICH2 (7.7.10/2.3.2), gcc (8.3.0), APEX (8ba5090), and Papi (5.7.0) The Octo-Tiger source code is available on Github. To run the simulation run: octotiger --config_file=rcb.ini --silo_num_groups=n where n is the number of nodes.