use python3 for server

README.md

@@ -29,7 +29,7 @@ in root of the repo.
 
 ##### Python
 ```
-python -m SimpleHTTPServer 8080
+python3 -m http.server 8080
 ```
 And api spec will render on [http://localhost:8080](http://localhost:8080).
 
@@ -78,7 +78,7 @@ https://www.npmjs.com/package/@chainsafe/eth2.0-api-wrapper
 
    - Make sure info.version in beacon-node-oapi.yaml file is updated before tagging.
    - CD will create github release and upload bundled spec file
-   
+
 2. Add release entrypoint in index.html
 
 In SwaggerUIBundle configuration (inside index.html file), add another entry in "urls" field (SwaggerUI will load first item as default).