Fix assertion error for superuser

[lordlabuckdas]

In test_snare_helpers_check_privileges.py, since a superuser would have (write) permissions for the root directory, 2 of the assertions fail.

So, I have used os.geteuid() to get the effective user ID and set self.privileges accordingly.

I have also removed the executable permissions for snare_helpers.py as it is not required.

[glaslos]

I find this test a bit confusing. Are we testing here if we could run Snare on this system?

[lordlabuckdas]

Yes, we're testing the check_privileges function which is used to create a directory for Snare and handle cases where the user does not have sufficient permissions to do so. I believe this makes Snare more non-root-user-friendly.
I agree that this test does not make much sense if Snare is intended to only be run as root.