added validations to users and default for attempts
Merge branch 'master' of https://github.com/ctailor2/flashcards_project into new_seeds

This needs to be added so that we can have the default value of an attempt be set to
false, and to make sure that all registration credentials are present and unique.
tweaked the Salamander name issue
Merge pull request #8 from ctailor2/new_seeds

New seeds