Bump gulp-shell from 0.5.2 to 0.8.0

Bumps [gulp-shell](https://github.com/sun-zheng-an/gulp-shell) from 0.5.2 to 0.8.0.
- [Release notes](https://github.com/sun-zheng-an/gulp-shell/releases)
- [Commits](sun-zheng-an/gulp-shell@0.5.2...0.8.0)

---
updated-dependencies:
- dependency-name: gulp-shell
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -11,7 +11,7 @@
     "gulp-postcss": "6.1.1",
     "gulp-replace": "0.5.4",
     "gulp-sass": "2.3.2",
-    "gulp-shell": "0.5.2",
+    "gulp-shell": "0.8.0",
     "gulp-sourcemaps": "1.6.0",
     "gulp-uglify": "1.5.4",
     "jquery": "1.11.3",