chore(package): update @storybook/addon-storyshots to version 5.3.18

Closes #84

Author: greenkeeper[bot]

package.json

@@ -59,7 +59,7 @@
     "@storybook/addon-a11y": "^5.3.18",
     "@storybook/addon-actions": "^5.3.18",
     "@storybook/addon-links": "^5.3.18",
-    "@storybook/addon-storyshots": "^4.0.0-alpha.2",
+    "@storybook/addon-storyshots": "^5.3.18",
     "@storybook/react": "^4.0.0-alpha.2",
     "@storybook/storybook-deployer": "^2.3.0",
     "aws-sdk": "^2.217.1",