Variable: added a Python test for the isEquivalentVariable() method.
Variable: added a Python test for the isEquivalentVariable() method.

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