The Demo app Doesn't compile for tvOS

[reubensjohn]

• I've read, understood, and done my best to follow the *CONTRIBUTING guidelines.

What did you do?

ℹ Try building the demo for tvOS

What did you expect to happen?

ℹ I was expecting the code to compile for tvOS and I could run the demo in AppleTV as th etarget

What happened instead?

ℹ The demo project failed to compile. with error UISlider not available in tvOS

Charts Environment

Charts version 3.4.0/Branch-master/Commit Number: NA
Xcode version: 11.3.1
Swift version: 5.1
Platform(s) running Charts: tvOS
macOS version running Xcode: catalina 10.15.4

Demo Project

ℹ Please link to or upload a project we can download that reproduces the issue.

[liuxuan30]

I don't think we have a TV demo app