feat: Enable API Hub (#485)

* feat: add support for api hub #461

* WIP: add api hubs apis #461

* WIP: add api hubs apis #461

* WIP: add api hubs apis #461

* feat: enable api hub apis

* feat: enable other apis for API Hub

* feat: enable runtime attachments to API Hub

* feat: enable prj registrations to API Hub

* chore: add unit tests for API Hub

* feat: create apihub instances

* feat: adds support for updates

* chore: gofumpt files

* chore: gofumpt files

* feat: adds support to export APIs

* chore: gofumpt files

* bug: uncomment crt attribute

* bug: check if allowedValues is present

* bug: address review comments

* feat: write contents of spec to a file

* bug: fixes incorrect descriptions

* bug: fixes params for deployments

* Fixed UpdateCmd for deployments and externalAPIs

* feat: adds capability to update api version

* bug: fixes flag naming to be consistent

* bug: fixes struct for api version

---------

Co-authored-by: Kurt Kanaskie <[email protected]>

internal/apiclient/options.go

@@ -30,7 +30,7 @@ const (
 )
 
 // registryBaseURL is the Apigee API Hub control plane endpoint
-const registryBaseURL = "https://apigeeregistry.googleapis.com/v1/projects/%s/locations/%s"
+const registryBaseURL = "https://apihub.googleapis.com/v1/projects/%s/locations/%s"
 
 // baseDRZURL is the Apigee control plane endpoint
 const baseDRZURL = "https://%s-apigee.googleapis.com/v1/organizations/"
@@ -334,7 +334,7 @@ func GetApigeeRegistryURL() (registryURL string) {
 	if options.ProjectID == "" {
 		options.ProjectID = options.Org
 	}
-	return fmt.Sprintf(registryBaseURL, options.ProjectID, registryRegion)
+	return fmt.Sprintf(registryBaseURL, options.ProjectID, options.Region)
 }
 
 // GetApigeeBaseURL