I faced the same issue when i was using the stack exchange API  to post a message to stack overflow website.
            
    I figured I had to post my application on a domain name .I hosted my application on free domain provided by 000webhost.com .You may wish to take a similar approach .
        
    After deploying the application on the domain , change the oauth domain and the application website on the app edit page .  Also , Keep in mind you have to link a valid stack apps post (a post made by you on stack apps) in the edit page .
        
    This should work.