Feature/data manage

[m-jewel]

From UpdatedRequirements.pdf:

7. Title: Data management for Pre-populated data Description: Admin, should be able to go on the data management page and create new data for Period, Material, and Cultures table which can be used in future to make creating new projectile points easier. Admins should be able to delete a previously made period, culture, or material which in turn will delete that respective attribute value from the projectile point table as well because we are using cascade and foreign keys. There should be a confirmation dialog before deleting anything to prevent user errors.

[m-jewel]

Commented out some tests awaiting a patch for issue #123. Will add back after issue is resolved