Merge pull request #802 from daira/book-remove-makefile #4032

Job	Run time
Book tests	1m 31s
Bitrot check	1m 32s
Build target wasm32-unknown-unknown	1m 54s
Build target wasm32-wasi	1m 43s
Code coverage	21m 25s
Intra-doc links	1m 31s
Rustfmt	15s
Test on i686-unknown-linux-gnu	13m 26s
Test on ubuntu-latest	7m 15s
Test on i686-unknown-linux-gnu with beta features	13m 22s
Test on windows-latest	9m 50s
Test on i686-unknown-linux-gnu with nightly features	15m 0s
Test on macOS-latest	12m 20s
Test on ubuntu-latest with beta features	7m 23s
Test on windows-latest with beta features	9m 31s
Test on macOS-latest with beta features	7m 25s
Test on ubuntu-latest with nightly features	8m 14s
Test on windows-latest with nightly features	11m 16s
Test on macOS-latest with nightly features	9m 14s
	2h 34m 7s

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