Merge pull request #1 from elenasharma/model_and_migration

Configured database tables and models for users, questions, answers, vot...
Merge pull request #2 from elenasharma/model_and_migration

created the correct nested associations for the routes and migrations.  ...
CRUD outline; working on getting users/questions relationship linked
Pulled down questions_crud branch
completed edit, update, and delete for questions