Added migrations and models for Quiz DataBase
just fixed notation
reverted schema and DB files from master
Added model and  migration for Comment class
Added Quiz status enumeration
changed status enum to old-ruby syntax, added Quiz delete and queryAll methods
fixed syntax error
Merge pull request #28 from SoftServeUniversity/AssessmentsModelsMigrationsSeeds

Assessments models,  migrations and seeds for Quiz
Merged master into register branch. Resolved conflicts