fixed dropwizzard endpoints

For this class something like this would be useful as a way to standardise the exception handling:

```
public class JedisException extends Exception {
    ...
}

public abstract class RedisAction<T> {
    public abstract T execute(Jedis jedis) throws Exception;
    
    public T handleException(Exception e) throws Exception {
        throw e;
    }
}

public <T> T execute(RedisAction<T> action) throws JedisException {
    Jedis jedis = this.borrow();
    try {
        return action.execute(jedis);
    } catch (Exception e) {
        try {
            return action.handleException(e);
        } catch (Exception ee) {
            throw new JedisException(ee);
        }
    } finally {
        this.revert(jedis);
    }
}

public void set(final String key, final String value) throws JedisException {
    this.execute(new RedisAction<Void>() {
        @Override
        public Void execute(Jedis jedis) throws Exception {
             jedis.set(key, value);
             return null;
        }
    });
}
```