Typo in description of challenge 7

[sbmohler]

Challenge 7 in part 2 of the workshop should read as follows:
"Use .groupby() to find the maximum unemployment rate for each country. Sort your results from largest to smallest.
Use the example above for guidance."

It currently reads:
"Use .groupby() to find the maximum unemployment rate for European Union and non-European Union countries. Sort your results from largest to smallest.
Use the example above for guidance."