Add support for tvOS download in Pods

[rat-moonshine]

Currently, it raises error while installing pod against a tvOS project:

[!] The platform of the target MontagePreview(tvOS 13.2) is not compatible withMJPEGStreamLib (0.2.1), which does not support tvOS.

I confirm the lib works well while using in tvOS 13.2 projects separately.

Please, add support to download the lib for tvOS projects, too. Thanks!

[kuraydev]

Hello @rat-moonshine,
Thank you for reaching me and using this library :)
I will add this support this weekend however, I cannot test it for tvOS I guess. Please help me for testing it while making this support :)

[rat-moonshine]

You can test it very easily though by downloading against a tvOS XCode project, I guess :)

Let me know if you need a help separately!