Add missing file functional_tests/attributes.py.

Author: progval

functional_tests/attributes.py

@@ -0,0 +1,18 @@
+class Foo:
+    bar = 5
+    print(bar)
+
+print('---')
+
+print(Foo.bar)
+
+f = Foo()
+print(f.bar)
+
+f.bar = 6
+print(Foo.bar)
+print(f.bar)
+
+Foo.bar = 7
+print(Foo.bar)
+print(f.bar)