fix(app-preview): add key prop to select.item component

[Aboubakary833]

Component / Package Name:

This PR contains:

• [x] bugfix
• [ ] feature
• [ ] refactor
• [ ] documentation
• [ ] other

Are tests included?

• [ ] yes (bugfixes and features will not be merged without tests)
• [x] no

Breaking Changes?

• [] yes (breaking changes will not be merged unless absolutely necessary)
• [x] no

Fixes #123

Description

Added missing key to Select.Item component in mobile.jsx file.

[shellscape]

@lordelogos tests didn't run bc of a lint error

[lordelogos]

@lordelogos tests didn't run bc of a lint error

Fixed! @shellscape