[BUG] Build error caused by broken changes in a dependency

The `ethereum-types` crate is failed to build because of the certain changes in bitvec. 
Related issue: https://github.com/bitvecto-rs/bitvec/issues/105

So, `bitvec` used by `parity-scale-codec`,
`parity-scale-codec` used by `impl-codec`,
`impl-codec` used by `primitive-types`,
`primitive-types` used by `ethereum-types`.