Rename SASS tests to SCSS, since they're using SCSS syntax

tests/syntax-tests/source/SCSS/LICENSE.md

@@ -0,0 +1,25 @@
+This file has been copied from https://sass-lang.com/documentation/syntax
+
+
+LICENSE:
+
+
+Copyright (c) 2006-2018 Hampton Catlin, Natalie Weizenbaum, Chris Eppstein, and
+Jina Anne
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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