fix spelling
text should be renderd at the center of the node
add support for testing js
add className to Node
change 'New' style to match with the others
add ui test scenario
refactoring click_button function
Add Link representation
refactoring function calls
fix id generation bug
add acceptance test for adding a child node
add id generation for Node
add class name for Node, Link
add 'Add a child node' button
implement addChildNode()
Merge new changes