Bump percy from 0.18.4 to 0.19.1 (#70)

Bump percy from 0.18.4 to 0.19.1

Author: hacknug

package.json

@@ -46,7 +46,7 @@
     "eslint-plugin-standard": "^4.0.0",
     "npm-run-all": "^4.1.5",
     "parcel-plugin-bundle-visualiser": "^1.2.0",
-    "percy": "^0.18.2",
+    "percy": "^0.19.1",
     "postcss-cli": "^6.1.3",
     "postcss-fontpath": "^1.0.0",
     "posthtml-expressions": "^1.1.1",