CodeLens enabled for Turtle activities in 5.5

[celinelatulipe]

Describe the bug
In Section 5.5, there are two activities that use the Turtle module. Since CodeLens/PythonTutor doesn't support it, the CodeLens button shouldn't be enabled/visible.

To Reproduce
Steps to reproduce the behavior:

1. Go to Section 5.5
2. Scroll down to activity 5.5.2 and 5.5.3
3. Click on the Show CodeLens
4. Click on the 'Next' button in CodeLens
5. CodeLens shows: ImportError: turtle not found or not supported
   Only these modules can be imported:
   future, abc, array, bisect, calendar, cmath,
   collections, copy, datetime, decimal, doctest, fractions,
   functools, hashlib, heapq, io, itertools, json,
   locale, math, operator, pickle, pprint, random,
   re, string, types, typing, unittest

Expected behavior
A clear and concise description of what you expected to happen. The CodeLens button shouldn't be shown since it doesn't support the Turtle module

[bnmnetp]

This is easy to fix by just adding a :nocodelens: parameter to the activecode directive.