fix: added variables to the constants file.

fix: updated sql queries with constants

lib/constants.js

@@ -3,4 +3,13 @@ const anonymousCustomer = {
   name: 'anonymous'
 }
 
-module.exports = {anonymousCustomer}
+const AUTHENTICATOR_ISSUER_ENTITY = 'Lamassu'
+const AUTH_TOKEN_EXPIRATION_TIME = '30 minutes'
+const REGISTRATION_TOKEN_EXPIRATION_TIME = '30 minutes'
+
+module.exports = {
+  anonymousCustomer,
+  AUTHENTICATOR_ISSUER_ENTITY,
+  AUTH_TOKEN_EXPIRATION_TIME,
+  REGISTRATION_TOKEN_EXPIRATION_TIME
+}