Read SESSION_TYPE from config file rather than hardcode

Author: rayluo

app.py

@@ -7,7 +7,7 @@
 
 
 app = Flask(__name__)
-app.config["SESSION_TYPE"] = "filesystem"  # We choose to store tokens in server-side session
+app.config.from_object(app_config)
 Session(app)
 
 

app_config.py

@@ -19,3 +19,5 @@
 # https://docs.microsoft.com/en-us/graph/permissions-reference
 SCOPE = ["https://graph.microsoft.com/Calendars.Read"]
 
+SESSION_TYPE = "filesystem"  # So token cache will be stored in server-side session
+