Found the answer to my question here http://nginx.org/en/docs/http/ngx_http_core_module.html#location

"If a location is defined by a prefix string that ends with the slash character, and requests are processed by one of proxy_pass, fastcgi_pass, uwsgi_pass, scgi_pass, or memcached_pass, then the special processing is performed. In response to a request with URI equal to this string, but without the trailing slash, a permanent redirect with the code 301 will be returned to the requested URI with the slash appended. If this is not desired, an exact match of the URI and location could be defined like this"