Fixes #97

[grabbou]

In jest (test runner) and react-native environment, the assignment is going to be ignored and the self remains pointing to whatever react-native defined for the sake of testing. Adding missing var here.

CC: @davidaurelio

[imhotep]

Same as Issue #96. I need a test that shows that the global breaks something.

[imhotep]

But since it's pretty minor I add your change anyway.

[Kureev]

I need a test that shows that the global breaks something.

Well, here we go: https://github.com/facebook/react-native/pull/7899/files#diff-781111e0db5cf5c6cc9b56a63fdfcbf6R31 test breaks on this line.

That's the source: https://github.com/facebook/react-native/blob/master/local-cli/rnpm/link/src/ios/addFileToProject.js

[grabbou]

In general, I consider this as a type error... I can't think of any case where assigning to global context would be desirable (also - esp. that we overwrite that for every new PbxFile). BTW - we don't need it at all in that case actually, passing this would have the same effect.