Pyscss is obsolete with Dart CSS complier; remove all pyscss code.

third_party/pyscss/scss/tests/test_extend.py

-import unittest
-
-from scss.parser import Stylesheet
-
-
-class TestSCSS( unittest.TestCase ):
-
-    def setUp(self):
-        self.parser = Stylesheet(options=dict(compress=True))
-
-    def test_extend(self):
-        src = """
-        .error {
-            border: 1px #f00;
-            background-color: #fdd;
-        }
-        .error .intrusion {
-            background-image: url("/image/hacked.png");
-        }
-        .seriousError {
-            @extend .error;
-            border-width: 3px;
-        }
-        """
-        test = ".error, .seriousError{border:1px #f00;background-color:#fdd}.error .intrusion, .seriousError .intrusion{background-image:url('/image/hacked.png')}.seriousError{border-width:3px}"
-        out = self.parser.loads(src)
-        self.assertEqual(test, out)