testcase for broken environment cleanup
cleanup env by unloading App instead of recreating

It is safer and easier to let OTP handle resetting of the environment
back to its original state, rather than trying to mimic this behavior.
On top of that, the attempted behavior did not take into account that a
configuration file can reference other configuration files.
Merge pull request #2 from spil-rob/shared_deps_pr

Improved env cleanup