Reset rspec
Eliminate exam number from database
Add factory for Encounters
Eliminate unneeded index on true-false questions
Improve whitespace.  Add seed files
Add encounter structure for four levels
Add structure for missions page
Add title to encounter.  Clean up code.
Add index for true/false questions
Add index for short answer questions
Add index for missions
Add validations to mission
Add validation to short answer question model
Add seed data for missions
Add friendly ids for physics jokes
Add friendly ids to missions
Add friendly id to encounters along with associated validations to encounter title
Add title to short answer questions and true false questions
Add friendly ids to short answer questions and true false questions
Add links to mission index