Switch to 2017.7 as default

Change-Id: Idd06e869f946dbbff4173b2eeb2f3e54a4ff6707
diff --git a/tcp_tests/settings.py b/tcp_tests/settings.py
index a645aff..34103a1 100644
--- a/tcp_tests/settings.py
+++ b/tcp_tests/settings.py
@@ -82,4 +82,4 @@
     'TEMPEST_EXCLUDE_TEST_ARGS',
     '--blacklist-file mcp_pike_lvm_skip.list')
 TEMPEST_TARGET = os.environ.get('TEMPEST_TARGET', 'gtw01')
-SALT_VERSION = os.environ.get('SALT_VERSION', '2016.3')
+SALT_VERSION = os.environ.get('SALT_VERSION', '2017.7')