Enforce usage of sqlite3 for running tests

- Simplifies tests by creating a database in memory
- Does not affect the user setup at all

InvenTree/InvenTree/settings.py

@@ -159,7 +159,19 @@ WSGI_APPLICATION = 'InvenTree.wsgi.application'
 
 DATABASES = {}
 
+"""
+When running unit tests, enforce usage of sqlite3 database,
+so that the tests can be run in RAM without any setup requirements
+"""
+if 'test' in sys.argv:
+    eprint('Running tests - Using sqlite3 memory database')
+    DATABASES['default'] = {
+        'ENGINE': 'django.db.backends.sqlite3',
+        'NAME': 'test_db.sqlite3'
+    }
+
 # Database backend selection
+else:
     if 'database' in CONFIG:
         DATABASES['default'] = CONFIG['database']
     else: