Add test to check out of bounds error in getError.
Add test to check out of bounds error in getError.

MichaelClerx/libcellml,MichaelClerx/libcellml,cellml/libcellml,hsorby/libcellml,nickerso/libcellml,nickerso/libcellml,cellml/libcellml,cellml/libcellml,libcellml/buildbot-testing,cellml/libcellml,hsorby/libcellml,libcellml/buildbot-testing,hsorby/libcellml,nickerso/libcellml,MichaelClerx/libcellml,nickerso/libcellml,hsorby/libcellml