Disable a spio scr test that requires hdf5 in configurations w/o hdf5

Author: kennyweiss

src/axom/sidre/examples/spio/CMakeLists.txt

@@ -30,9 +30,13 @@ foreach(src ${spio_example_sources})
         )
 endforeach()
 
-if(SCR_FOUND AND AXOM_ENABLE_TESTS)
-    # Note: This example is a combination of a test and an example due
-    # inability to run two SCR executables at the same time
+if(SCR_FOUND AND AXOM_ENABLE_TESTS AND HDF5_FOUND)
+    # Note: This example is a combination of a test and an example
+    # since we're unable to run two SCR executables at the same time
+    #
+    # The test was written against the sidre_hdf5 protocol, so disable it
+    # in configurations that do not include hdf5
+    
     axom_add_executable(
         NAME       spio_IO_SCR_Checkpoint_ex
         SOURCES    IO_SCR_Checkpoint.cpp