fix(tests): override engine options for sqlite

Author: palkerecsenyi

invenio_pidstore/__init__.py

@@ -36,6 +36,7 @@
 >>> from flask import Flask
 >>> app = Flask('myapp')
 >>> app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite://'
+>>> app.config['SQLALCHEMY_ENGINE_OPTIONS'] = {}
 
 You initialize PIDStore like a normal Flask extension, however Invenio-PIDStore
 is dependent on Invenio-DB so you need to initialize both extensions: