Unmet peer dependency.

I get this warning when installing into React `v15.4.2`:

```
├── UNMET PEER DEPENDENCY react@15.4.2
└── react-p5-wrapper@0.0.3

npm WARN react-p5-wrapper@0.0.3 requires a peer of react@^0.14.0 but none was installed.
```

My `package.json` looks like this:

```
{
  /* stuff */

  "dependencies": {
    "react": "15.4.2",
    /* everything else */
  }
}