Merge pull request #207 from nervosnetwork/fix-coverage-makefile #587

Job	Run time
Checks / Format	11s
Checks / Clippy	7m 33s
Tests / Build & Test (ubuntu-latest)	13m 55s
Tests / Build & Test (Wasm)	5m 31s
Tests / Build & Test (macos-latest)	8m 22s
Tests / Build & Test (windows-2019)	15m 44s
Code Coverage (ubuntu-latest)	12m 28s
	1h 3m 44s

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