Update ethereum-types requirement from 0.14.0 to 0.15.1

Updates the requirements on [ethereum-types](https://github.com/paritytech/parity-common) to permit the latest version.
- [Commits](paritytech/parity-common@ethereum-types-v0.14.0...ethereum-types-v0.15.1)

---
updated-dependencies:
- dependency-name: ethereum-types
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Cargo.toml

@@ -12,7 +12,7 @@ keywords = ["abi", "ethereum", "solidity", "web3"]
 
 [dependencies]
 anyhow = { version = "1.0", default-features = false, features = ["std"] }
-ethereum-types = { version = "0.14.0", default-features = false, features = ["std"] }
+ethereum-types = { version = "0.15.1", default-features = false, features = ["std"] }
 hex = { version = "0.4", default-features = false, features = ["std"] }
 nom = { version = "7.0", default-features = false, features = ["std"] }
 regex = { version = "1.5", default-features = false, features = ["std"] }
@@ -23,4 +23,4 @@ tiny-keccak = { version = "2.0", default-features = false, features = ["keccak"]
 [dev-dependencies]
 pretty_assertions = "1.0"
 rand = "0.8"
-ethereum-types = "0.14.0"
+ethereum-types = "0.15.1"