[WIP] More Test Suite Improvements

Assorted things related to tests:

 - [x] the batch file is gone and replaced with a leaner, meaner Powershell script 
 - [x] if you've got a `OCTOKIT_GITHUBCLIENTID` and `OCTOKIT_CLIENTSECRET` defined (as well as your credentials), the build script will fetch a token from the GitHub API and set it in the environment variables
 - [ ] this token should be validated in subsequent sessions to ensure it hasn't been revoked
 - [x] some clown forgot to update his integration tests to actually follow a rule he specified in #243 
 - [ ] document the changes so that contributors can get back to work
 - [ ] ???