Rule order should be normalised for multiple class selectors

[andrewnicols]

Take two files:

a.css

.a.b.c {
  font-color: transparent;
}

b.css

.b.c.a {
  font-color: transparent;
}

css-compare does not normalise the order of the multiple class selectors leading to a large number of false positives.

2020 nicols@boysenberry:~/git/tmp/scss> css-compare -c a.css -t b.css
Index: b.css
===================================================================
--- b.css
+++ b.css
@@ -1,3 +1,3 @@
-.a.b.c {
+.b.c.a {
   font-color: transparent;
 }
\ No newline at end of file