chapter-09 exercises - using Swift

1. Fork this repo
2. Clone your fork
3. Follow along with the examples from Chapter 9 in the Learning Mobile App Development textbook.
4. Complete exercises 1 through 4 at the end of chapter 9

• Add a Lastname Label and TextInput UI elements to the Hello world screen
• Write Swift code to test whether both First name and Last name are empty and change the output label to "Hello World"
• Make several format changes to the UI elements on the storyboard including fonts, colors, sizes, layout, etc.
• Add a "Clear" button to the storyboard and include code to reset the output label to "Hello" when the button is clicked

5. Commit your changes and Push to your repo
6. Create a Pull Request for me to grade