import os

SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL', 'sqlite://')

ACCESS_TOKEN = os.environ.get('ACCESS_TOKEN')
PAGE_ID = os.environ.get('PAGE_ID')
APP_ID = os.environ.get('APP_ID')
VERIFY_TOKEN = os.environ.get('VERIFY_TOKEN')

import os

SQLALCHEMY_DATABASE_URI = os.environ['DATABASE_URL']

ACCESS_TOKEN = os.environ['ACCESS_TOKEN']
PAGE_ID = os.environ['PAGE_ID']
APP_ID = os.environ['APP_ID']
VERIFY_TOKEN = os.environ['VERIFY_TOKEN']

--- 
+++ 
@@ -1,8 +1,8 @@
 import os
 
-SQLALCHEMY_DATABASE_URI = os.environ['DATABASE_URL']
+SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL', 'sqlite://')
 
-ACCESS_TOKEN = os.environ['ACCESS_TOKEN']
-PAGE_ID = os.environ['PAGE_ID']
-APP_ID = os.environ['APP_ID']
-VERIFY_TOKEN = os.environ['VERIFY_TOKEN']
+ACCESS_TOKEN = os.environ.get('ACCESS_TOKEN')
+PAGE_ID = os.environ.get('PAGE_ID')
+APP_ID = os.environ.get('APP_ID')
+VERIFY_TOKEN = os.environ.get('VERIFY_TOKEN')
Make server ignore missing environment variables

This is by far the best solution for setup, CI and testing purposes.
