Use DuniterPy IPv{4,6} regexes to get rid of `ipaddress` dependency. `ipaddress` is used in `silkaj.network_tools.check_ip()` to determine the IP address version. As a first step, it can be replaced with stdlib `re` regex module and `duniterpy.constants.IPV{4,6}_REGEX` regexes. As a second step (#177), replace `silkaj.network_tools.{parse_endpoint(),endpoint_type(),check_ip()}` with `duniterpy.api.endpoint.{,Secured}BMAEndpoint`. May be a useless step, since we will move to GVA(Endpoint).