Correct spelling in tests/resources/level1-3.xml.
Correct spelling in tests/resources/level1-3.xml.

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