Missing dev-dependencies into the new created project

[blixit]

Following the npm readme leads me to notice that some dev-dependencies are not listed in the package.json file.
Considering adding them will avoid to get many successive errors when trying to build the library.
Here is the list of packages I personaly installed to make the command npm run build:lib work :
"del": "^3.0.0",
"fs": "0.0.1-security",
"fs-extra": "^7.0.0",
"gulp": "^3.9.1",
"gulp-autoprefixer": "^5.0.0",
"gulp-clean-css": "^3.9.4",
"gulp-htmlmin": "^4.0.0",
"gulp-if": "^2.0.2",
"gulp-replace": "^0.6.1",
"gulp-sass": "^3.2.1",
"path": "^0.12.7",
"rimraf": "^2.6.2",
"rollup": "^0.54.0",
"run-sequence": "^2.2.1",
"sorcery": "^0.10.0",
"sync-json": "^1.0.2",
"through2": "^2.0.3",