changed spec variable names to 'previous_node' and 'next_node' to avoid naming conflicts
added @previous_value and @next_value to Node class initializer
started coding List.push
started coding List.pop
changed '@previous_value' to '@prev_value' globally and instituted Node accessor -- node.rb RSPEC tests passing
instituted attr_accessor for List class
added attr_reader :length for List class
required 'node.rb' inside list.rb
List.push and List.pop now passing RSPEC
coding '[]' method for List class
fixed '[]' method and is now passing RSPEC
coded '[]=' method for List class to pass RSPEC
started 'insert' method for List class to pass one RSPEC test
reduced 'insert' method for List class to pass 'insert into empty list' RSPEC test
only one RSPEC failing: 'can insert at the end of the list'
implemented and refactored 'insert' method for List class -- all RSPEC tests passing -- only 'shift' and 'unshift' left