Update dependency gulp-svgstore to v9

Author: renovate[bot]

package.json

@@ -63,7 +63,7 @@
     "gulp-hub": "^4.2.0",
     "gulp-rename": "^1.2.2",
     "gulp-svgmin": "^1.2.4",
-    "gulp-svgstore": "^6.1.1",
+    "gulp-svgstore": "^9.0.0",
     "material-design-icons": "^3.0.1",
     "ts-node": "~4.1.0",
     "tslint": "~5.9.1",