index.ipynb: Update TODO list

Author: jnareb

index.ipynb

@@ -168,7 +168,7 @@
     "   - [ ] interactive visualizations\n",
     "   - [ ] version control graphs (LARGE)\n",
     "     - [x] git in Python _(somewhat: shell vs GitPython)_\n",
-    "     - [ ] cloning repository, generating graph of commits\n",
+    "     - [x] cloning repository, generating graph of commits\n",
     "     - [ ] saving data to file, restoring data from file\n",
     "     - [ ] repositories to use: git, linux kernel\n",
     "     - [ ] graph statistics\n",