Extracted Splashpage from Conference

#418
```
[17:03] <differentreality> the answer to the root path failiing test is what I wrote in the channel...
[17:03] <differentreality> in the controller you load_and_authorize the resource of splashpage model
[17:03] <differentreality> but you have not added an ability for the SplashPage model...
[17:04] <differentreality> so the authorization fails there before it ever hits the show action, I think.
```

@differentreality I'm not sure if I understand you correct ... I already added Splashpage to ability (line 110) and the problem is that the show will be hit and not redirected to root path! Could you please have a look at this again? Thanks :)

@hennevogel