Switch default dev env to vagrant VM

… and document that !

README.md

@@ -79,18 +79,58 @@ See the end of this README for a reference of available configuration settings.
 Database
 --------
 
-At this point, you should setup your database. The default setting
-uses SQLite but some features will not be available, namely:
+At this point, you should setup your database. You have two options.
+
+### With PostgreSQL (for developpement), recomended
+
+The official database for coin is postgresql.
+
+To ease developpement, a postgresql virtual-machine recipe is provided
+through [vagrant](https://vagrantup.com).
+
+
+**Note: Vagrant is intended for developpement only and is totaly unsafe for a
+production setup**.
+
+Install requirements:
+
+    sudo apt install virtualbox vagrant
+
+Then, to boot and configure your dev VM:
+
+    vagrant up
+
+Default settings target that vagrant+postgreSQL setup, so, you don't have to
+change any setting.
+
+
+### With SQLite
+
+SQLite setup may be simpler, but some features will not be available, namely:
 
 - automatic allocation of IP subnets (needs proper subnet implementation in
   the database)
 - sending automated emails to remind of expiring membership fee
   (needs aggregation on date fields, see Django doc)
 
-If you want to use those features, you will need to setup a PostgreSQL
-database.
-
-For more information on the database setup, see https://www.illyse.org/projects/ils-si/wiki/Mise_en_place_environnement_de_dev
+To use sqlite instead of PostgreSQL, you have
+to [override local settings](#settings) with someting like:
+
+```python
+DATABASES = {
+    # Base de donnée du SI
+    'default': {
+        'ENGINE': 'django.db.backends.sqlite3',
+        'NAME': 'coin.sqlite3',
+        'USER': '', # Not needed for SQLite
+        'PASSWORD': '', # Not needed for SQLite
+        'HOST': '',  # Empty for localhost through domain sockets
+        'PORT': '',  # Empty for default
+    },
+}
+```
+
+### For both PostgreSQL and SQLite
 
 The first time, you need to create the database, create a superuser, and
 import some base data to play with:

coin/settings_base.py

@@ -19,14 +19,14 @@ ADMINS = (
 MANAGERS = ADMINS
 
 DATABASES = {
-    # Base de donnée du SI
+    # Database hosted on vagant test box
     'default': {
-        'ENGINE': 'django.db.backends.sqlite3',
-        'NAME': 'coin.sqlite3',
-        'USER': '', # Not needed for SQLite
-        'PASSWORD': '', # Not needed for SQLite
-        'HOST': '',  # Empty for localhost through domain sockets
-        'PORT': '',  # Empty for default
+        'ENGINE': 'django.db.backends.postgresql_psycopg2',
+        'NAME': 'coin',
+        'USER': 'coin',
+        'PASSWORD': 'coin',
+        'HOST': 'localhost',  # Empty for localhost through domain sockets
+        'PORT': '15432',  # Empty for default
     },
 }