Merge pull request #23 from catherinev/question_tests

Question tests
added model answer spec and nothing broke
added answer model validations and nothing broke
added belongs to question to answer model and nothing broke
added tests for model and view, view still incomplete
Merge pull request #24 from catherinev/answers_test_km

Answers test km
Merge branch 'master' of https://github.com/rickytux/DBCoverflow into question_tests
"merge test branches"