make test expects / creates nodeHomeDir in default directory (~/.regen) instead of TempDirs

[clevinson]

Describe the bug
Tests should be self contained. I originally noticed this issue in app/regen/cmd/TestInitCmd() and addressed in in #285. But after clearing my go test cache realize that the problem still persists, and there are probably a number of CLI tests that expect (& create if doesn't exist) a config dir in $HOME.

We probably have to do some sleuthing around to find all tests that this applies to. I assume a similar problem exists on the SDK repo with ~/.simapp.

To Reproduce
Steps to reproduce the behavior:

1. rm -rf ~/.regen
2. make test
3. ls -l ~/.regen (returns a valid config dir)

Expected behavior
make test should not interact with a user's local defaultNodeHome (e.g. ~/.regen), and should rather create TempDirs.

[ryanchristo]

Unable to reproduce. It looks like we are using temp directories in all tests now.