I think this specify the json dependency directly, rather than relying on resteasy. Maybe either:
```
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.4</version>
        </dependency>
```

or

```
<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-mapper-asl</artifactId>
    <version>1.9.13</version>
</dependency>
```

Or maybe it should come from the user? I'm not sure if that's possible with maven because these two have different packages.