Updating NPM dependencies

node_modules/gcp-metadata/README.md

@@ -25,7 +25,15 @@ console.log(data); // ... All metadata properties
 #### Access specific properties
 ```js
 const data = await gcpMetadata.instance('hostname');
-console.log(data) // ...Instance hostname
+console.log(data); // ...Instance hostname
+const projectId = await gcpMetadata.project('project-id');
+console.log(projectId); // ...Project ID of the running instance
+```
+
+#### Access nested properties with the relative path
+```js
+const data = await gcpMetadata.instance('service-accounts/default/email');
+console.log(data); // ...Email address of the Compute identity service account
 ```
 
 #### Access specific properties with query parameters
@@ -62,4 +70,15 @@ console.log(id.toString()) // ... 4520031799277581759
 [codecov-image]: https://codecov.io/gh/googleapis/gcp-metadata/branch/master/graph/badge.svg
 [codecov-url]: https://codecov.io/gh/googleapis/gcp-metadata
 [npm-image]: https://img.shields.io/npm/v/gcp-metadata.svg
-[npm-url]: https://www.npmjs.com/package/gcp-metadata
+[npm-url]: https://www.npmjs.com/package/gcp-metadata
+
+### Environment variables
+
+* GCE_METADATA_HOST: provide an alternate host or IP to perform lookup against (useful, for example, you're connecting through a custom proxy server).
+
+For example:
+```
+export GCE_METADATA_HOST = '169.254.169.254'
+```
+
+* DETECT_GCP_RETRIES: number representing number of retries that should be attempted on metadata lookup.