Bump to debian:sid-20201012 and ES 7.12.0; add PyPy

Fast-forward to debian:sid-20201012-slim, which is the last snapshot
before Python 3.9 became the default in Debian

Install PyPy (pypy3 7.3.2) for speed improvement; see OpenDRR/opendrr-api#137

Refresh most Python libraries from Debian packages, and avoid building
psycopg2 from source:

 - python3-numpy: 1.19.2 (was 1.18.5)
 - python3-pandas: 1.0.5 (was 1.0.4)
 - python3-psycopg2: 2.8.5 (was 2.6)
 - python3-psycopg2cffi: 2.8.1 (newly added)
 - python3-requests: 2.23.0 (was 2.23.0)
 - python3-sqlalchemy: 1.3.19 (was 1.3.17)

From PyPI using pip3:

 - elasticsearch: 7.12.0 (was 7.7.1)

Install git 2.30.2 and git-lfs 2.13.2 from Debian 11 (bullseye)
as the old git-lfs 2.11.0 hangs at "GIT_LFS_SKIP_SMUDGE=1 git checkout".

Move installation of extra utilities needed by add_data.sh from
OpenDRR/opendrr-api python/Dockerfile to this repo:

 - dos2unix eatmydata jq moreutils nano time

Add org.opencontainers.image.* labels

Clean up /var/lib/apt/lists/* to further save space.

Image size has been reduced from 662MB to 561MB.

Dockerfile

@@ -27,23 +27,32 @@
 #
 # =================================================================
 
-FROM debian:sid-20200720-slim
-
-LABEL maintainer="Joost van Ulden <[email protected]>" 
+FROM debian:sid-20201012-slim
 
+LABEL org.opencontainers.image.authors="Joost van Ulden <[email protected]>, Anthony Fok <[email protected]>"
 LABEL org.opencontainers.image.source="https://github.com/opendrr/python-env"
+LABEL org.opencontainers.image.version="1.1.0"
+LABEL org.opencontainers.image.vendor="Government of Canada"
+LABEL org.opencontainers.image.licenses="MIT"
 
 # copy required files
 COPY . .
 
 RUN echo 'Acquire::Check-Valid-Until "false";' > /etc/apt/apt.conf.d/docker-snapshot.conf && \
-    sed -i '/snapshot.debian.org/s/^# //; /deb.debian.org/s/^/# /; s/20200720/20200731/' /etc/apt/sources.list && \
-    apt-get update && apt-get dist-upgrade -y && \
-    apt-get install -y libpq-dev gcc curl git-lfs gdal-bin python3-pip && \
-    pip3 install psycopg2~=2.6 && \
-    apt-get autoremove -y gcc && \
-    apt-get install -y postgresql-client && \
-    sed -i '/snapshot.debian.org/s/^/# /; /deb.debian.org/s/^# //' /etc/apt/sources.list && \
-    pip3 install --upgrade pip && pip install -r requirements.txt
+    sed -i '/snapshot.debian.org/s/^# //; /deb.debian.org/s/^/# /' /etc/apt/sources.list && \
+    echo "deb http://deb.debian.org/debian bullseye main" >> /etc/apt/sources.list && \
+    echo 'Package: *\n\
+Pin: release n=bullseye\n\
+Pin-Priority: 50' > /etc/apt/preferences.d/git-in-bullseye && \
+    cat /etc/apt/preferences.d/git-in-bullseye && \
+    apt-get update && \
+    apt-get install -y --no-install-recommends \
+        curl gdal-bin postgresql-client \
+        dos2unix eatmydata jq moreutils nano time \
+        python3-numpy python3-pandas python3-psycopg2 python3-psycopg2cffi \
+        python3-requests python3-sqlalchemy pypy3 python3-pip && \
+    apt-get install -y --no-install-recommends -t bullseye git git-lfs && \
+    pip3 install elasticsearch==7.12.0 && \
+    rm -rf /var/lib/apt/lists/*
 
 ENV PYTHONUNBUFFERED 1