Minor amendment to #276

Author: krassowski

docs/Installation.ipynb

@@ -130,7 +130,7 @@
     "\n",
     "RUN conda install --quiet --yes --freeze-installed \\\n",
     "    'python-language-server' \\\n",
-    "    'jupyterlab=2.1' \\\n",
+    "    'jupyterlab={JUPYTERLAB_VERSION}' \\\n",
     "    'r-languageserver' \\\n",
     "  && python3 -m pip install --no-cache-dir --no-deps \\\n",
     "    'jupyter-lsp={JUPYTER_LSP_VERSION}' \\\n",