Use PostgreSQL rather than SQLite.
Added VocabWord model
added game model
added player model
Added GameQuestion model that keeps track of questions in game
changed column names to snake case
made combo of first_name last_name  unique
Created Question table that lists the correct answer, and user responce
added IncorrectAnswer model
Removed the GameQuestion model and added game_id to Question
deleted unneeded files. Also created answer model. Added methods that checks correct and incorrect answers
Correct name of players table to lower case; make username unique and relax unique constraint on first + last name
Correct reference to player_id by using standard `references` approach
Correct typo
Use standard `references` approach for vocab_questions.game_id; player_answer is an integer (word location index)
Remove vocab_ from model names; it is redundant since this is the vocab app :-)
Added model relationships
These two methods are questions you can ask about a Question object, so we make them instance methods on the Question class
Typo fix
Merge pull request #1 from qiuey00/nick/initial_models_fixes

Nick/initial models fixes