Actual Package Install Tests

[shama]

Probably a good idea to pick or create actual packages to install, update and remove in the test suite. The current tests just double check the results but don't actually do any installing.

[RobLoach]

Would this install and test packages at sys_get_temp_dir()? Similar to LibraryInstallerTest?

[shama]

Yep. That looks like a good test to model after.