Creating rubric, rubric_category, and rubric_submissions models, migrations, associations
created rubric, rubric_categories objects and controllers and created nested new rubric form

This commit includes rubrics/new working with nested form for to create a new rubric and categories
nested working with hardcoded number of categories
Created pages for creating a new rubric, and updating existing rubric.

This is a work in progress commit. Do not merge this branch yet.
Merge branch 'master' into rubric_branch
Merge branch 'master' into rubric_branch
rubric new, show, edit pages are complete
Merge pull request #82 from whoisglover/rubric_branch

Rubric new, edit, show