remove multiple calls to content method

I kept having the error when trying to run the tests:

```
LoadError: cannot load such file -- ProMotion
/Users/.../ios/motionapps/ProMotion/Rakefile:9:in `require'
/Users/.../ios/motionapps/ProMotion/Rakefile:9:in `<top (required)>'  
```


I Don't know what caused it, but when I ran `bundle exec rake spec`, It worked fine.