must add gasUsedRatio to getFeeHistory #3
Description
must add gasUsedRatio to getFeeHistory https://github.com/makinghappen/web3dart/blob/master/lib/src/core/client.dart#L297
like in 214b935#diff-6fbcc7254ef1460041d04e65580b4c8e9ae83e161ae730a257fe11557e2a3414R23