message: added watch functionality
diff: +const pkg = require("./package.json");
  +const rollup = require("rollup");
  +const rollupTypescript = require("rollup-plugin-typescript2");
  +const { watch, series } = require("gulp");
  const gulp = require("gulp"),
  concat = require("gulp-concat"),
  sourcemaps = require("gulp-sourcemaps"),
  @@ -5,9 +9,6 @@ const gulp = require("gulp"),
  insert = require("gulp-insert"),
  deleteLines = require("gulp-delete-lines"),
  uglify = require("gulp-uglify");
  -const rollup = require("rollup");
  -const rollupTypescript = require("rollup-plugin-typescript2");
  -const pkg = require("./package.json");
  gulp.task("build", () => {
  return rollup
  @@ -58,3 +59,8 @@ gulp.task("clean", () => {
  gulp.task("default", gulp.series("build", "clean"), () => {
  console.log("... dist/pptxgen.min.js done!");
  });
  +
  +// Watch
  +exports.default = function() {
  + watch("src/*.ts", series("build", "clean"));
  +};
  