message: Rename registerSignatureKeyTypes to register
  This was done in the new TypeScript public API with all the other primitive types, but signature was missed by mistake.
diff: @@ -7,7 +7,7 @@ export * from './sign';
  export * from './verify';
  export {ecdsaP256IeeeEncodingKeyTemplate, ecdsaP256KeyTemplate, ecdsaP384IeeeEncodingKeyTemplate, ecdsaP384KeyTemplate, ecdsaP521IeeeEncodingKeyTemplate, ecdsaP521KeyTemplate} from './ecdsa_for_signing';
  -export function registerSignatureKeyTypes() {
  +export function register() {
  ecdsaForSigning.register();
  ecdsaForVerifying.register();
  signWrapper.register();
  