Test that check() catches wrong order of elements

Fails --- next commit will tighten test.

example/eigen.py

@@ -24,6 +24,8 @@ ref = np.array(
 def check(mat):
     return 'OK' if np.sum(mat - ref) == 0 else 'NOT OK'
 
+print("should_give_NOT_OK = %s" % check(ref[:, ::-1]))
+
 print("fixed_r = %s" % check(fixed_r()))
 print("fixed_c = %s" % check(fixed_c()))
 print("pt_r(fixed_r) = %s" % check(fixed_passthrough_r(fixed_r())))

example/eigen.ref

+should_give_NOT_OK = NOT OK
 fixed_r = OK
 fixed_c = OK
 pt_r(fixed_r) = OK