Add new yasnippet for Python unittesting

snippets/python-mode/new_unittest

@@ -0,0 +1,9 @@
+# -*- mode: snippet -*-
+# name: New unittest
+# key: testdef
+# --
+    def test_${1:name}(self):
+        """${2:docstring}
+        """
+
+        $0self.assertTrue(False)