fix(package): update gulp-typescript to version 4.0.0 (#2209)
fix(package): update gulp-typescript to version 4.0.0 (#2209)


JohnnyQQQQ/angular-seed-material2,dmitriyse/angular2-seed,mgechev/angular-seed,hookom/climbontheway,dmitriyse/angular2-seed,hookom/climbontheway,mgechev/angular2-seed,dmitriyse/angular2-seed,vyakymenko/angular-seed-express,pieczkus/whyblogfront,pieczkus/whyblogfront,JohnnyQQQQ/angular-seed-material2,vyakymenko/angular-seed-express,hookom/climbontheway,mgechev/angular-seed,JohnnyQQQQ/angular-seed-material2,mgechev/angular2-seed,vyakymenko/angular-seed-express,hookom/climbontheway,mgechev/angular2-seed,pieczkus/whyblogfront,mgechev/angular-seed,dmitriyse/angular2-seed