Add 'Debug simple typo with guidance' challenge (#65)

Signed-off-by: Merwane Hamadi <merwanehamadi@gmail.com>

agbenchmark/challenges/code/code.py

@@ -0,0 +1,8 @@
+import pytest
+
+from agbenchmark.challenge import Challenge
+
+
+@pytest.mark.code
+class CodeChallenge(Challenge):
+    """Challenge for memory"""