Update README.md (pulumi#1278)

change public_ip to nginx_public_ip in README.md

gcp-py-network-component/README.md

@@ -89,14 +89,14 @@ can be composed into a higher-level, reusable abstraction.
 1. Get the IP address of the newly-created instance from the stack's outputs: 
 
  ```bash
- $ pulumi stack output public_ip
+ $ pulumi stack output nginx_public_ip
  13.64.196.146
  ```
 
 1. Check to see that your server is now running:
 
  ```bash
- $ curl http:https://$(pulumi stack output public_ip)
+ $ curl http:https://$(pulumi stack output nginx_public_ip)
  Powered by Pulumi!
  ```
 
@@ -121,7 +121,7 @@ can be composed into a higher-level, reusable abstraction.
 
  Outputs:
  - network : "demo-7a734d7"
- - public_ip: "34.66.58.210"
+ - nginx_public_ip: "34.66.58.210"
 
  Resources:
  - 11 to delete
@@ -143,7 +143,7 @@ can be composed into a higher-level, reusable abstraction.
 
  Outputs:
  - network : "demo-7a734d7"
- - public_ip: "34.66.58.210"
+ - nginx_public_ip: "34.66.58.210"
 
  Resources:
  - 11 deleted