message: Tweak return type spacing for function type declarations.
diff: @@ -1741,6 +1741,7 @@ function genericPrintNoParens(path, options, print) {
  ]);
  case "TSFunctionType":
  + case "TSConstructorType":
  return concat([
  path.call(print, "typeParameters"),
  "(",
  @@ -1850,11 +1851,13 @@ function genericPrintNoParens(path, options, print) {
  var parent = path.getParentNode(0);
  var prefix = ": ";
  var isFunctionType = namedTypes.TSFunctionType.check(parent);
  - if (namedTypes.TSFunctionType.check(parent))
  + if (namedTypes.TSFunctionType.check(parent)) {
  prefix = " => ";
  + }
  - if(namedTypes.TSTypePredicate.check(parent))
  + if (namedTypes.TSTypePredicate.check(parent)) {
  prefix = " is ";
  + }
  return concat([
  prefix,
  