fix pip env error

tubearchivist/web/Dockerfile

@@ -5,9 +5,9 @@ RUN apt-get clean && apt-get -y update && \
     python3-dev libpq-dev build-essential \
     vim htop bmon net-tools iputils-ping procps
 
+ENV PATH=/root/.local/bin:$PATH
 COPY requirements.txt /requirements.txt
-RUN pip install --upgrade pip setuptools && \
-    pip install --no-cache-dir -r /requirements.txt --src /usr/local/src
+RUN pip install --user -r requirements.txt
 
 RUN mkdir /data