chore(deps-dev): bump handlebars from 4.5.3 to 4.7.7

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.5.3 to 4.7.7.
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/handlebars-lang/handlebars.js/blob/master/release-notes.md)
- [Commits](handlebars-lang/handlebars.js@v4.5.3...v4.7.7)

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

package.json

@@ -165,7 +165,7 @@
     "gulp-imagemin": "4.1.0",
     "gulp-rename": "1.2.2",
     "gulp.spritesmith": "6.9.0",
-    "handlebars": "4.5.3",
+    "handlebars": "4.7.7",
     "html-reporter": "2.12.3",
     "husky": "3.1.0",
     "jest": "^24.9.0",