tests/test_utils.h: added copyright and use #pragma once.
tests/test_utils.h: added copyright and use #pragma once.

cellml/libcellml,hsorby/libcellml,nickerso/libcellml,nickerso/libcellml,nickerso/libcellml,MichaelClerx/libcellml,cellml/libcellml,nickerso/libcellml,hsorby/libcellml,hsorby/libcellml,hsorby/libcellml,MichaelClerx/libcellml,MichaelClerx/libcellml,cellml/libcellml,cellml/libcellml