Changing the criteria for maximumRadicalElectrons.

Prior to this, single atoms were allowed to bypass this criteria,
but this is neither well documented or intuitive.  We should get rid of it,
especially since we can now individually allow seed mech and input species
to bypass constraints.

Author: connie

rmgpy/rmg/model.py

@@ -1741,6 +1741,6 @@ def failsSpeciesConstraints(self, species):
             return True
         if len(struct.atoms) - H > maxHeavyAtoms:
             return True
-        if (struct.getNumberOfRadicalElectrons() > maxRadicals) and (len(struct.atoms) - H > 1):
+        if (struct.getNumberOfRadicalElectrons() > maxRadicals):
             return True
         return False