chore(package): update rollup-plugin-filesize to version 8.0.0

Closes #122

Author: greenkeeper[bot]

package.json

@@ -51,7 +51,7 @@
     "react-styleguidist": "^11.0.4",
     "react-test-renderer": "^16.13.1",
     "rollup": "^2.2.0",
-    "rollup-plugin-filesize": "^6.2.1",
+    "rollup-plugin-filesize": "^8.0.0",
     "rollup-plugin-typescript2": "^0.27.0",
     "ts-jest": "^25.2.1",
     "ts-loader": "^6.2.2",