Populate all required variables with a distro check.

test/test_automated_install.py

@@ -278,6 +278,7 @@ def test_update_package_cache_success_no_errors(Pihole):
     ''' confirms package cache was updated without any errors'''
     updateCache = Pihole.run('''
     source /opt/pihole/basic-install.sh
+    distro_check
     update_package_cache
     ''')
     assert 'Updating local cache of available packages...' in updateCache.stdout
@@ -288,6 +289,7 @@ def test_update_package_cache_failure_no_errors(Pihole):
     mock_command('apt-get', {'*':('', '1')}, Pihole)
     updateCache = Pihole.run('''
     source /opt/pihole/basic-install.sh
+    distro_check
     update_package_cache
     ''')
     assert 'Updating local cache of available packages...' in updateCache.stdout