message: ignore incremental option in tsconfig
  fixes
diff: @@ -21,7 +21,7 @@ export class TypeScriptSource extends OptionsComponent {
  static IGNORED: string[] = [
  'out', 'version', 'help', 'emitDeclarationOnly',
  'watch', 'declaration', 'declarationDir', 'declarationMap', 'mapRoot',
  - 'sourceMap', 'inlineSources', 'removeComments'
  + 'sourceMap', 'inlineSources', 'removeComments', 'incremental'
  ];
  initialize() {
  