Add version endpoint to nginx configuration (#316)

Signed-off-by: Aleksandar Novakovic <aleksandar.novakovic@mainflux.com>

docker/nginx.conf

@@ -153,6 +153,22 @@ http {
             }
         }
 
+        location /version {
+            proxy_redirect off;
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+            proxy_set_header X-Forwarded-Proto $scheme;
+            proxy_pass http://things:8182;
+
+            # Allow OPTIONS method CORS
+            if ($request_method = OPTIONS ) {
+                add_header Content-Length 0;
+                add_header Content-Type text/plain;
+                return 200;
+            }
+        }
+
         # Proxy pass to mainflux-http-adapter
         location /http/ {
             proxy_redirect off;