updating hadoop Q a bit
showing explanation below answer
schema update for interview q
adding quiz answer + explanatino
adding simple_format for explanation
 adding exact answer as an option for interview questions
changing autogradable answer flash
disabling sanitize for simple_format
adding the first set of solutions
adding exact answer form
adding migration for adding explanation to interview Q
Don't show the link when it's nil
Only show the next question button when there is a next question
Fix typo in the word question
Merge pull request #1204 from teamleada/mark-interview-questions-bug

Fix interview question next answer bug
Adding answer to the last bit of interview questions.
typo
small gramma
QA-ing answers
merge + letting users know that there are no more questions