Simplify Crab token system #893

Job	Run time
Task check format	24s
Task check features (runtime/darwinia)	1m 24s
Task check features (runtime/crab)	1m 36s
Task check features (runtime/pangoro)	1m 42s
Task check features (runtime/pangolin)	1m 20s
Task build darwinia	47m 21s
Task test darwinia	11m 27s
Task check EVM	5m 4s
Task check runtimes (darwinia-dev, https://darwinia-rpc.darwiniacommunitydao.xyz)	58s
Task check runtimes (crab-dev, https://crab-rpc.darwiniacommunitydao.xyz)	1m 3s
Task check runtimes (pangoro-dev, https://pangoro-rpc.darwinia.network)	1m 4s
Task check runtimes (pangolin-dev, https://pangolin-rpc.darwinia.network)	59s
Task checks cleaning	4s
	1h 14m 26s

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