Bump bower from 1.8.4 to 1.8.8 in /mobile

Bumps [bower](https://github.com/bower/bower) from 1.8.4 to 1.8.8.
- [Release notes](https://github.com/bower/bower/releases)
- [Changelog](https://github.com/bower/bower/blob/master/CHANGELOG.md)
- [Commits](bower/bower@v1.8.4...v1.8.8)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

mobile/package-lock.json

@@ -12,7 +12,7 @@
     "gulp-sass": "^2.0.4"
   },
   "devDependencies": {
-    "bower": "^1.3.3",
+    "bower": "^1.8.8",
     "cordova-plugin-file": "~4.3.3",
     "cordova-plugin-statusbar": "~2.2.2",
     "cordova-plugin-whitelist": "^1.3.4",