fixing typo
updating homework
Homework for week 7, attempt 1.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	05BasicSQL/homework.txt
	07AdvancedQuerying/exercises.txt
fixing queries in q6
adding homework for chapters 8 and 9
adding chapter 10 homework
adding optional exercises to chapter 10
Merge remote-tracking branch 'upstream/master'

Conflicts:
	07AdvancedQuerying/exercises.txt
Merge remote-tracking branch 'upstream/master'
Homework for week 07.