Update lint to warning missing routes

@miwest929 @sheavalentine-mdsol @fosrias Please review and merge.

This PR makes `routes` section in API doc no longer critical. Therefore, lint will not throw error. Instead, warning will be raised alerting user. As I said many times - not really happy with this solution. I'm thinking about alternative solutions for error response. 
Should say ```reports a missing routes section warning when the routes section is missing```. Note ```warning``` not ```error```.