upgrade pip and setuptools before installing packages (certbot#4378)

Dockerfile-dev

@@ -51,15 +51,16 @@ COPY certbot-compatibility-test /opt/certbot/src/certbot-compatibility-test/
 COPY tests /opt/certbot/src/tests/
 
 RUN virtualenv --no-site-packages -p python2 /opt/certbot/venv && \
+    /opt/certbot/venv/bin/pip install -U pip && \
+    /opt/certbot/venv/bin/pip install -U setuptools && \
     /opt/certbot/venv/bin/pip install \
     -e /opt/certbot/src/acme \
     -e /opt/certbot/src \
     -e /opt/certbot/src/certbot-apache \
     -e /opt/certbot/src/certbot-nginx \
     -e /opt/certbot/src/letshelp-certbot \
     -e /opt/certbot/src/certbot-compatibility-test \
-    -e /opt/certbot/src[dev,docs] && \
-    /opt/certbot/venv/bin/pip install -U setuptools
+    -e /opt/certbot/src[dev,docs]
 
 # install in editable mode (-e) to save space: it's not possible to
 # "rm -rf /opt/certbot/src" (it's stays in the underlaying image);