Resolve "Passing the keyword argument as ..." deprecation warning

[abicky]

This PR resolves a deprecation warning like below when the Ruby version is 2.7:

/path/to/ruby-kafka/spec/transaction_manager_spec.rb:594: warning: Passing the keyword argument as the last hash parameter is deprecated /path/to/ruby-kafka/spec/transaction_manager_spec.rb:682: warning: The called method `txn_offset_commit_response' is defined here 

Before

% rspec --tag functional spec/transaction_manager_spec.rb:601 spec/functional/consumer_group_spec.rb:438 Run options: include {:functional=>true, :locations=>{"./spec/transaction_manager_spec.rb"=>[601], "./spec/functional/consumer_group_spec.rb"=>[438]}} exclude {:performance=>true, :fuzz=>true} Kafka::TransactionManager #send_offsets_to_txn currently in transaction /Users/arabiki/ghq/src/github.com/zendesk/ruby-kafka/spec/transaction_manager_spec.rb:594: warning: Passing the keyword argument as the last hash parameter is deprecated /Users/arabiki/ghq/src/github.com/zendesk/ruby-kafka/spec/transaction_manager_spec.rb:682: warning: The called method `txn_offset_commit_response' is defined here notifies transaction coordinator Consumer API /Users/arabiki/ghq/src/github.com/zendesk/ruby-kafka/spec/spec_helper.rb:66: warning: Using the last argument as keyword parameters is deprecated; maybe ** should be added to the call /Users/arabiki/ghq/src/github.com/zendesk/ruby-kafka/spec/spec_helper.rb:70: warning: The called method `create_topic' is defined here consuming messages with a custom assignment strategy Finished in 3.72 seconds (files took 0.72687 seconds to load) 2 examples, 0 failures 

After

% rspec --tag functional spec/transaction_manager_spec.rb:601 spec/functional/consumer_group_spec.rb:438 Run options: include {:functional=>true, :locations=>{"./spec/transaction_manager_spec.rb"=>[601], "./spec/functional/consumer_group_spec.rb"=>[438]}} exclude {:performance=>true, :fuzz=>true} Kafka::TransactionManager #send_offsets_to_txn currently in transaction notifies transaction coordinator Consumer API consuming messages with a custom assignment strategy Finished in 3.72 seconds (files took 0.61582 seconds to load) 2 examples, 0 failures 

[dasch]

Thanks!