Migrate rackspace/gophercloud -> gophercloud/gophercloud

Update vendor libraries

vendor/github.com/gophercloud/gophercloud/openstack/auth_env.go

@@ -0,0 +1,52 @@
+package openstack
+
+import (
+	"os"
+
+	"github.com/gophercloud/gophercloud"
+)
+
+var nilOptions = gophercloud.AuthOptions{}
+
+// AuthOptionsFromEnv fills out an identity.AuthOptions structure with the settings found on the various OpenStack
+// OS_* environment variables.  The following variables provide sources of truth: OS_AUTH_URL, OS_USERNAME,
+// OS_PASSWORD, OS_TENANT_ID, and OS_TENANT_NAME.  Of these, OS_USERNAME, OS_PASSWORD, and OS_AUTH_URL must
+// have settings, or an error will result.  OS_TENANT_ID and OS_TENANT_NAME are optional.
+func AuthOptionsFromEnv() (gophercloud.AuthOptions, error) {
+	authURL := os.Getenv("OS_AUTH_URL")
+	username := os.Getenv("OS_USERNAME")
+	userID := os.Getenv("OS_USERID")
+	password := os.Getenv("OS_PASSWORD")
+	tenantID := os.Getenv("OS_TENANT_ID")
+	tenantName := os.Getenv("OS_TENANT_NAME")
+	domainID := os.Getenv("OS_DOMAIN_ID")
+	domainName := os.Getenv("OS_DOMAIN_NAME")
+
+	if authURL == "" {
+		err := gophercloud.ErrMissingInput{Argument: "authURL"}
+		return nilOptions, err
+	}
+
+	if username == "" && userID == "" {
+		err := gophercloud.ErrMissingInput{Argument: "username"}
+		return nilOptions, err
+	}
+
+	if password == "" {
+		err := gophercloud.ErrMissingInput{Argument: "password"}
+		return nilOptions, err
+	}
+
+	ao := gophercloud.AuthOptions{
+		IdentityEndpoint: authURL,
+		UserID:           userID,
+		Username:         username,
+		Password:         password,
+		TenantID:         tenantID,
+		TenantName:       tenantName,
+		DomainID:         domainID,
+		DomainName:       domainName,
+	}
+
+	return ao, nil
+}