Add create ui for roadmaps

[anselb]

• Added ExtendableList.js component
• Updated RubricEdit.js component
• Added state in the local RubricEdit.js component
• Added server requests in the local RubricEdit.js component

TODO:

• Move state to Redux store
• Refactor the code to render the components as a wizard
• Allow the RubricEdit form to be used as an edit form as well
• Add errors if parts of the rubric aren't filled out and user tries to submit
• Allows parts of the rubric, and their children, to be deleted with a confirmation box
• Add more description as to what each part is for in a rubric
• Auto save with Debouce

[Jeffchiucp]

Resolve the file conflict?