[typo] - package.json

because npm sayes:

```

npm WARN package.json toobusy@0.2.3 No repository field.
npm WARN package.json toobusy@0.2.3 'repositories' (plural) Not supported.
npm WARN package.json Please pick one as the 'repository' field
npm WARN package.json hiredis@0.1.15 No repository field.

```