Change all variables in CredentialHelper.cs to private
Merge branch 'dev' of https://github.com/AzureRT/azure-sdk-tools into dev
1. Fix warnings (FxCop)
2. Refactor functional tests into three separate classes
3. Refactor VM size tests into separate tests
4. Fix a typo (Custon -> Custom)
Updating BVT tests
Merge pull request #31 from hyonholee/dev

Refactoring tests and fixing test issues.