Set OptionalCatchTestLauncher when testing with MPI

Now test names are deduced similarly to sequential unit tests

Fixes #2

tests/CMakeLists.txt

@@ -40,14 +40,7 @@ enable_testing()
 ParseAndAddCatchTests(unit_tests)
 
 if(${PASTIS_HAS_MPI})
-  add_test(mpi_unit_tests ${MPIEXEC} ${MPIEXEC_NUMPROC_FLAG} 3 "--oversubscribe"
-    ${MPIEXEC_PREFLAGS}
-    ${PASTIS_BINARY_DIR}/mpi_unit_tests
-    ${MPIEXEC_POSTFLAGS})
-else()
-  add_test(mpi_unit_tests ${PASTIS_BINARY_DIR}/mpi_unit_tests)
+set(OptionalCatchTestLauncher ${MPIEXEC} ${MPIEXEC_NUMPROC_FLAG} 3 --oversubscribe --path ${PASTIS_BINARY_DIR})
 endif()
-
-# Should patch ParseAndAddCatchTests macro to allow additional command parameter
-# to launch tests
-set_tests_properties("mpi_unit_tests" PROPERTIES FAIL_REGULAR_EXPRESSION "No tests ran" LABELS "mpi")
+ParseAndAddCatchTests(mpi_unit_tests)
+unset(OptionalCatchTestLauncher)