Run tests on multiple Python versions and databases (#424)

* Test against more python versions

* Add testing on MySQL

* Add testing on PostgreSQL

src/pretix/settings.py

@@ -10,8 +10,11 @@ from pkg_resources import iter_entry_points
 from . import __version__
 
 config = configparser.RawConfigParser()
-config.read(['/etc/pretix/pretix.cfg', os.path.expanduser('~/.pretix.cfg'), 'pretix.cfg'],
-            encoding='utf-8')
+if 'PRETIX_CONFIG_FILE' in os.environ:
+    config.read([os.environ.get('PRETIX_CONFIG_FILE')], encoding='utf-8')
+else:
+    config.read(['/etc/pretix/pretix.cfg', os.path.expanduser('~/.pretix.cfg'), 'pretix.cfg'],
+                encoding='utf-8')
 
 BASE_DIR = os.path.dirname(os.path.dirname(__file__))
 DATA_DIR = config.get('pretix', 'datadir', fallback=os.environ.get('DATA_DIR', 'data'))

src/pretix/testutils/settings.py

@@ -4,6 +4,7 @@ import tempfile
 
 tmpdir = tempfile.TemporaryDirectory()
 os.environ.setdefault('DATA_DIR', tmpdir.name)
+os.environ.setdefault('PRETIX_CONFIG_FILE', 'test/sqlite.cfg')
 
 from pretix.settings import *  # NOQA
 
@@ -33,10 +34,3 @@ CACHES = {
         'BACKEND': 'django.core.cache.backends.dummy.DummyCache',
     }
 }
-
-DATABASES = {
-    'default': {
-        'ENGINE': 'django.db.backends.sqlite3',
-        'NAME': ':memory:'
-    }
-}

src/tests/travis_mysql.cfg

@@ -0,0 +1,7 @@
+[database]
+backend=mysql
+name=pretix
+user=root
+password=
+host=127.0.0.1
+port=3306

src/tests/travis_postgres.cfg

@@ -0,0 +1,6 @@
+[database]
+backend=postgresql_psycopg2
+name=pretix
+user=postgres
+password=
+host=localhost