Wk3 hwk & Wk2 hwk updates

Only the files in the folders are updated. Key updates:
- Final Project / Proposal
- Week 3 / API GOV P2V2 (minor updates to clean up the detail message)
- Week 3 / Apt_Main 
- Week 3 / lib (classes for Apt_Main)
- Week 3 / SecretNumber
- Week 3 / lib_sn (classses for SecretNumber)
This line is confusing. My initial expectation was that the `if` statement was incorrect. It would be clearer to define a variable in another line, then use that variable in this line. For example,

`"You have #{guesses_remaining} chance#{"s" if guesses_remaining != 1} remaining."`