Pin setuptools version to 44.1.1, since 45.0.0 has error with Python 2.7

    pypa/setuptools#1964

Author: Feras A. Saad

docs/virtualenvs.md

@@ -42,7 +42,7 @@ sudo apt-get update -qq && \
 $ virtualenv --system-site-packages /path/to/venv
 $ . /path/to/venv/bin/activate
 $ pip install --upgrade pip
-$ pip install ipykernel==4.8.2 notebook==5.2.1
+$ pip install setuptools==44.1.1 ipykernel==4.8.2 notebook==5.2.1
 ```
 
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