Update mailman-web to use Python 3 (For rolling releases) (#217)

* Update mailman-web to use Python 3

* Update configuration

* Python 3.6 image.

* Use alpine 3.7

* Use new style middleware

* Use alpine 3.6

* In Python 3, urlparse was renamed to urllib.parse

.circleci/config.yml

@@ -49,7 +49,7 @@ workflows:
   scheduled-workflow:
     triggers:
       - schedule:
-          cron: "@weekly"
+          cron: "0 0 * * *"
           filters:
             branches:
               only: master

web/Dockerfile.dev

@@ -1,4 +1,4 @@
-FROM python:2.7-alpine3.6
+FROM python:3.6-alpine3.6
 
 MAINTAINER Abhilash Raj
 

web/docker-entrypoint.sh

@@ -16,7 +16,7 @@ function wait_for_postgres () {
 
 function wait_for_mysql () {
 	# Check if MySQL is up and accepting connections.
-	HOSTNAME=$(python -c "from urlparse import urlparse; o = urlparse('$DATABASE_URL'); print(o.hostname);")
+	HOSTNAME=$(python -c "from urllib.parse import urlparse; o = urlparse('$DATABASE_URL'); print(o.hostname);")
 	until mysqladmin ping --host "$HOSTNAME" --silent; do
 		>&2 echo "MySQL is unavailable - sleeping"
 		sleep 1

web/mailman-web/settings.py

@@ -100,7 +100,7 @@ INSTALLED_APPS = (
 )
 
 
-MIDDLEWARE_CLASSES = (
+MIDDLEWARE = (
     'django.contrib.sessions.middleware.SessionMiddleware',
     'django.middleware.common.CommonMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',