Add a tvOS build target

[didiercf]

I am currently working on a small tvOS project with ReactNative and trying to read and write files using this library but there doesn't seem to be a build target for tvOS which refrains me from linking the library.

Here are the libraries and versions:

• react-native: 0.54.1
• react-native-fetch-blob: 0.10.8

The error message that shows up is exactly the same as in the issue #251 to which the solution was to link the library, but since I'm working on tvOS and there was no build I think it causes the issue to stay.

I'm not 100% sure the issue comes from the missing build target so if anybody knows the fix to this I'm open to anything!

[oleksandr-yefremov]

Correct. There is no tvOS target, and theoretically you could use iOS target, if it did not contain any iOS specific code (like DocumentDir, which is not available on tvOS).
In this project contributors decided to change DocumentDir to CacheDir on tvOS, which should also work here in react-native-fetch-blob. But I am not sure it's worth the efforts, since official Blob has landed and has almost the same feature set.