tests: Add tests for attrtuple, and for more corner cases.

tests/basics/attrtuple1.py

@@ -0,0 +1,11 @@
+# test attrtuple
+# we can't test this type directly so we use sys.implementation object
+
+import sys
+t = sys.implementation
+
+# test printing of attrtuple
+print(str(t).find("version=") > 0)
+
+# test read attr
+print(isinstance(t.name, str))