chore(package): update @storybook/addon-knobs to version 5.0.0

Author: greenkeeper[bot]

package.json

@@ -44,7 +44,7 @@
     "@babel/preset-env": "^7.3.1",
     "@babel/preset-react": "^7.0.0",
     "@storybook/addon-actions": "^5.0.0",
-    "@storybook/addon-knobs": "^4.1.11",
+    "@storybook/addon-knobs": "^5.0.0",
     "@storybook/addon-links": "^4.1.11",
     "@storybook/addon-storyshots": "^4.1.11",
     "@storybook/addons": "^5.0.0",