Captialize "API" in this error message.

Signed-off-by: Matt Moyer <moyerm@vmware.com>

cmd/pinniped/cmd/kubeconfig.go

@@ -171,7 +171,7 @@ func runGetKubeconfig(ctx context.Context, out io.Writer, deps kubeconfigDeps, f
 
 	// Validate api group suffix and immediately return an error if it is invalid.
 	if err := groupsuffix.Validate(flags.concierge.apiGroupSuffix); err != nil {
-		return fmt.Errorf("invalid api group suffix: %w", err)
+		return fmt.Errorf("invalid API group suffix: %w", err)
 	}
 
 	execConfig := clientcmdapi.ExecConfig{

cmd/pinniped/cmd/kubeconfig_test.go

@@ -536,13 +536,13 @@ func TestGetKubeconfig(t *testing.T) {
 			`),
 		},
 		{
-			name: "invalid api group suffix",
+			name: "invalid API group suffix",
 			args: []string{
 				"--concierge-api-group-suffix", ".starts.with.dot",
 			},
 			wantError: true,
 			wantStderr: here.Doc(`
-				Error: invalid api group suffix: a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')
+				Error: invalid API group suffix: a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')
 			`),
 		},
 		{

cmd/pinniped/cmd/login_oidc_test.go

@@ -125,7 +125,7 @@ func TestLoginOIDCCommand(t *testing.T) {
 			`),
 		},
 		{
-			name: "invalid api group suffix",
+			name: "invalid API group suffix",
 			args: []string{
 				"--issuer", "test-issuer",
 				"--enable-concierge",
@@ -136,7 +136,7 @@ func TestLoginOIDCCommand(t *testing.T) {
 			},
 			wantError: true,
 			wantStderr: here.Doc(`
-				Error: invalid concierge parameters: invalid api group suffix: a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')
+				Error: invalid concierge parameters: invalid API group suffix: a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')
 			`),
 		},
 		{

cmd/pinniped/cmd/login_static_test.go

@@ -131,7 +131,7 @@ func TestLoginStaticCommand(t *testing.T) {
 			`),
 		},
 		{
-			name: "invalid api group suffix",
+			name: "invalid API group suffix",
 			args: []string{
 				"--token", "test-token",
 				"--enable-concierge",
@@ -142,7 +142,7 @@ func TestLoginStaticCommand(t *testing.T) {
 			},
 			wantError: true,
 			wantStderr: here.Doc(`
-				Error: invalid concierge parameters: invalid api group suffix: a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')
+				Error: invalid concierge parameters: invalid API group suffix: a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')
 			`),
 		},
 		{

pkg/conciergeclient/conciergeclient.go

@@ -109,7 +109,7 @@ func WithEndpoint(endpoint string) Option {
 func WithAPIGroupSuffix(apiGroupSuffix string) Option {
 	return func(c *Client) error {
 		if err := groupsuffix.Validate(apiGroupSuffix); err != nil {
-			return fmt.Errorf("invalid api group suffix: %w", err)
+			return fmt.Errorf("invalid API group suffix: %w", err)
 		}
 		c.apiGroupSuffix = apiGroupSuffix
 		return nil

pkg/conciergeclient/conciergeclient_test.go

@@ -111,16 +111,16 @@ func TestNew(t *testing.T) {
 				WithEndpoint("https://example.com"),
 				WithAPIGroupSuffix(""),
 			},
-			wantErr: "invalid api group suffix: [must contain '.', a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')]",
+			wantErr: "invalid API group suffix: [must contain '.', a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')]",
 		},
 		{
-			name: "invalid api group suffix",
+			name: "invalid API group suffix",
 			opts: []Option{
 				WithAuthenticator("jwt", "test-authenticator"),
 				WithEndpoint("https://example.com"),
 				WithAPIGroupSuffix(".starts.with.dot"),
 			},
-			wantErr: "invalid api group suffix: a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')",
+			wantErr: "invalid API group suffix: a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')",
 		},
 		{
 			name: "valid",