Starting to rewrite tests using NUnit and Fluent

Also separating unit and integration testing
Consolidated URLs to an array and fixed HTML URL
Issue tests written
Unauthenticated user tests
Repository tests
Refactoring and AuthTests

Now all tests extend WithGitHubApi so an API object is created for each
test
Also implemented an account to be used in tests
OrganizationTests
Removing old test account authorization extension
Forgot the testfixture attribute
Changed apitestaccount's email to be more unique
Wrote SearchTests
Finished Repository Tests
Removing old test project
Bye MSTest!
Seperating Json Tests from GistTests
Removed DotSettings file
Added GitHubApi tests
Merge pull request #7 from johnduhart/unittesting

Unit Testing Overhaul rationalizes Tests structure significantly and switches to NUnit from MSTest, which is nice.  Thanks, @johnduhart!