remove temporary file

Author: fangohr

book/18-environments.ipynb

@@ -1636,7 +1636,7 @@
    "id": "82715cd6",
    "metadata": {},
    "source": [
-    "**Tidy up**"
+    "**Tidy up**: remove files created in this section"
    ]
   },
   {
@@ -1647,16 +1647,9 @@
    "outputs": [],
    "source": [
     "!rm -rf /tmp/cowsay-python\n",
-    "!rm -rf myvirtualenv-copy"
+    "!rm -rf myvirtualenv-copy\n",
+    "!rm -f requirements.txt"
    ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "bd9e1fa3",
-   "metadata": {},
-   "outputs": [],
-   "source": []
   }
  ],
  "metadata": {