fix(security): Upgrade transitive hoek dep

Nivo is affected by https://nodesecurity.io/advisories/566. This is also
reported by Gemnasium and the reason for the red flag within the README.
This change upgrades `@storybook/react` which transitively depends on
`hoek`:

```
$ yarn why hoek
yarn why v1.3.2
[1/4] 🤔  Why do we have the module "hoek"...?
[2/4] 🚚  Initialising dependency graph...
[3/4] 🔍  Finding dependency...
[4/4] 🚡  Calculating file sizes...
info Has been hoisted to "hoek"
info This module exists because "@storybook/react#request#hawk" depends on it.
info Disk size without dependencies: "28MB"
info Disk size with unique dependencies: "28MB"
info Disk size with transitive dependencies: "28MB"
info Number of shared dependencies: 0
✨  Done in 0.81s.
```

The changes within this PR are the result of executing:

```
yarn upgrade @storybook/react
```