Replace #api_base_protocol with #use_ssl

Ensure that protocol is either http or https using boolean value instead of
string comparison. This removes Opencnam::Util.sanitize_protocol.
Declare Opencnam::Util#process_response as private
Extract #parse_response_date method from Opencnam::Util#process_response
Refactor and remove large if block in Opencnam::Util#process_response
Change #phone to accept a hash of options

Opencnam::Client#phone now takes a hash as the second argument. This should
better reflect the OpenCNAM v2 API. Format is defaulted to 'text'.
Change format support to only text and json

Further refactoring. Leaves only parsing methods in Opencam::Util.
Opencnam::Client#phone has a more defined purpose.