changes to reproducibilty

[grahamas]

Some changes that would make the reproducibility tutorial flow better:

• Make the "Do one thing at a time" example more relatable and so easier to present (i.e. not involving foos)
• Integrate the ticket generation into the seed section, so that the seed example that people compare is tickets rather than numbers
• Reorganize so that students notice that their edits to make the code more readable (removing magic numbers etc.) would be easier if the copied code were in a function
• Give repos explicit names, e.g. "writings" (not reprodicibility or origin)
• Get rid of single-line if-else statement, as it is unnecessarily confusing
• Include code example of dpois