Optimistic Kovan EtherscanProvider

[sammosna]

Describe the Feature

Please add Optimistic Kovan to EtherscanProvider: https://api-kovan-optimistic.etherscan.io

Code Example

getBaseUrl(): string {
        switch(this.network ? this.network.name: "invalid") {
            [...]
            case "optimistic-kovan":
                return "https:/\/api-kovan-optimistic.etherscan.io"
            default:
        }

        return logger.throwArgumentError("unsupported network", "network", this.network.name);
    }

[ricmoo]

Added in v5.7.0.

Thanks! :)