Improve LoadingOverlay Example

[cancan101]

• styles.spinner is used but never defined
• Currently the spinner is centered vertically but not horizontally. I think you want:

  background: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
  },

[niftylettuce]

@cancan101 Can you please clarify this or submit a pull request?

[niftylettuce]

See #36 - we will be refactoring this soon to support Android/iOS and not have any issues here, there will no longer be the XCode integration needed