logger is global, which leads to conflicts

[yegor256]

Currently, I have to do this (if I understand the API of the library correctly):

require 'jsonrpc/client'
require 'loog'
JSONRPC.logger = Loog::VERBOSE # instance of Logger class
c = JSONRPC::Client.new(url)
c.eth_call(...)

The configuration of the logger is global, while an instance of JSONRPC::Client is local. Making two instances of JSONRPC::Client in different places of the app leads to a question: which logger is used by which client? Obviously, it's not possible (or very inconvenient) to use different loggers for different clients. I suggest making logger a property of JSONRPC::Client, instead of being a property of the JSONRPC module.