Feat- Parse Shibboleth eduPersonAffiliationValues attribute

1. Set a valid set of eppa values
2. Check if user's attributes match with any of the valid set of eppa values
3. If no match with user's eppa and valid set, redir to shib error page

app/__init__.py

@@ -71,6 +71,7 @@ def create_app(config_name):
                                referrer=session['return_url'], cancel_url=vars.default_referrer,
                                welcome_msg=messages.welcome_message,
                                cancel_msg=messages.cancel_message,
+                               error_msg=messages.error_message)
 
     @app.route('/blocked_account')
     def account_block():