Check for / Fix memory leaks in unit tests #870

Job	Run time
CMake build on MacOS	8m 9s
CMake Serial Minimal Build on Linux	58s
CMake Serial With Clawpack Build on Linux	6m 53s
CMake Serial With Clawpack and HDF Build on Linux	8m 3s
CMake Serial With GeoClaw Build on Linux	1m 9s
CMake Serial With CudaClaw (CUDA 10.1) Build on Linux	2m 43s
CMake Serial With CudaClaw (CUDA 11.3) Build on Linux	3m 49s
CMake MPI Minimal Build on Linux	1m 18s
CMake MPI With Clawpack Build on Linux	7m 21s
CMake MPI With Clawpack and HDF Build on Linux	8m 39s
CMake MPI With GeoClaw Build on Linux	1m 56s
CMake MPI With CudaClaw (CUDA 10.1) Build on Linux	4m 20s
CMake MPI With CudaClaw (CUDA 11.3) Build on Linux	5m 0s
CMake MPI With ThunderEgg Build on Linux	3m 28s
	1h 3m 46s

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