Python 2.7 image with latest pip, pipenv and tox, headers and compilers.

Dockerfile

+FROM python:2.7-slim-stretch
+RUN apt-get update && \
+    DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
+        build-essential \
+        git \
+        libffi-dev \
+        libpq-dev \
+        libssl-dev \
+        zlib1g-dev \
+    && \
+    pip install --no-cache-dir --update pip tox pipenv | cat && \
+    rm -rf /tmp/* /var/tmp/* /var/lib/apt/lists/* /var/cache/apt/archives/* /root/.cache/*