Bump bower from 1.4.1 to 1.8.8 (#920)

Bumps [bower](https://github.com/bower/bower) from 1.4.1 to 1.8.8.
- [Release notes](https://github.com/bower/bower/releases)
- [Changelog](https://github.com/bower/bower/blob/master/CHANGELOG.md)
- [Commits](https://github.com/bower/bower/compare/v1.4.1...v1.8.8)

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

package.json

@@ -4,7 +4,7 @@
   "main": "main.js",
   "private": true,
   "devDependencies": {
-    "bower": "1.4.1",
+    "bower": "1.8.8",
     "gulp": "3.8.11",
     "gulp-rev": "4.0.0",
     "gulp-rev-replace": "0.4.1",