Update Docker image

- Remove Redis from the Docker image.
- Add Celery flower.
- Add Python 3 packages needed for in-container pip installs.
- Fix typos.
- Allow PIP proxying.

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

docker/rootfs/usr/local/bin/run_tests.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+export DEBIAN_FRONTEND=noninteractive
+
+apt-get update
+apt-get install -y --no-install-recommends gcc python-dev tesseract-ocr-deu
+
+su mayan -c "$MAYAN_PIP_BIN install -r ${MAYAN_INSTALL_DIR}/testing-base.txt"
+
+su mayan -c "$MAYAN_BIN test --mayan-apps --settings=mayan.settings.testing"