fix: Update nginx config to use dynamic DNS resolution

- Replace upstream blocks with resolver directive
- Use variables for backend addresses to avoid startup errors
- Simplify configuration with single server block
- Add health check endpoint

server/api/node_modules/fast-json-stable-stringify/.travis.yml

@@ -0,0 +1,8 @@
+language: node_js
+node_js:
+  - "8"
+  - "10"
+  - "12"
+  - "13"
+after_script:
+  - coveralls < coverage/lcov.info