small fix ch04-03 & code block typo ch07-02#2138

Merged

steveklabnik merged 2 commits intorust-lang:masterfrom

Nov 15, 2019

Commits on Nov 7, 2019

small fix ch04-03 line 161 'counting from 1'
danbugs
committed

Commits on Nov 14, 2019

removed typo in code block from ch07-02
danbugs
committed