Remove "Intermediate" slide option remove until content becomes available

Update menu for content selection "level" to not include "Intermediate" as content has not yet been developed.

![screen shot 2014-01-09 at 6 30 18 pm](https://f.cloud.github.com/assets/352082/1884162/ec998e96-7996-11e3-88af-ba0735acdae1.png)