Rust

Fix CI, update to Rust 2021, and update deps #147

Job	Run time
build (ubuntu-latest, stable)	1m 19s
build (ubuntu-latest, nightly)	1m 18s
build (windows-latest, stable)	2m 42s
build (windows-latest, nightly)	2m 34s
build (macos-latest, stable)	3m 30s
build (macos-latest, nightly)	3m 44s
test-macos (11.2)	22s
test-windows (11.2)	17s
test-macos (11.3)	23s
test-windows (11.3)	16s
test-linux (11.2)	20s
test-macos (11.4)	23s
test-linux (11.3)	27s
test-windows (11.4)	19s
test-macos (0.10.2)	25s
test-linux (11.4)	22s
test-windows (0.10.2)	19s
test-linux (0.10.2)	28s
	19m 28s

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