Formatting cleanup, fix test, add new test, and cleanup safely after test run

fun fact: ioutil.TempDir(TestDir, "removeVcs") was never succeeding because TestDir doesn't exist (this failure then silently passed through the rest of the test, which is why it leaves behind a "github.com/removeVcs" directory). This change moves the tests to actually run in a temp directory that gets cleaned up. And I added a dumb test - it's the first go code I've written that actually does anything, so idiomaticity may be missing.