chore(package): update imagemin-pngquant to version 7.0.0

Author: greenkeeper[bot]

package.json

@@ -25,7 +25,7 @@
 	"devDependencies": {
 		"eslint-config-fnd": "^1.6.0",
 		"imagemin-mozjpeg": "^8.0.0",
-		"imagemin-pngquant": "^6.0.0",
+		"imagemin-pngquant": "^7.0.0",
 		"imagemin-svgo": "^7.0.0",
 		"json-diff": "^0.5.2",
 		"npm-run-all": "^4.1.3",