Finish ex. 9.6.1
Finish ex. 9.6.2
Finish ex. 9.6.3
Finish ex. 9.6.5.  Ex. 9.6.4 was already done in previous optional exercises
Finished ex. 9.6.6 (without good specs)
Finish friendly redirect (9.2.3), which I forgot to do before starting the exercises
Finish ex. 9.6.8
Finish ex. 9.6.9, fix tests, and enhance custom matchers