Added coverage exceptions to rule message functions.

src/rules/integrals.py

@@ -67,7 +67,7 @@ def solve_indef(root, args):
     return substitute(Fx, x, b) - substitute(Fx, x, a)
 
 
-def solve_indef_msg(root, args):
+def solve_indef_msg(root, args):  # pragma: nocover
     return _('Solve indefinite integral {0} using substitution ' \
              'of %s with {0[2]} and {0[1]}.' % find_variable(root[0]))
 

src/rules/lineq.py

@@ -98,7 +98,7 @@ def subtract_term(root, args):
     return eq(left - term, right - term)
 
 
-def subtract_term_msg(root, args):
+def subtract_term_msg(root, args):  # pragma: nocover
     term = args[0]
 
     if term.negated == 1: