Add Salt 2018.3 tests

Change-Id: I9326d024809990b87482f08e2be93145cdeb8af1
diff --git a/.travis.yml b/.travis.yml
index 28df064..57426fa 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -20,15 +20,21 @@
   - bundle install
 
 env:
-  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2016.3 SUITE=client-compose
-  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2016.3 SUITE=client-container
-  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2016.3 SUITE=host-single
-  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=client-compose
-  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=client-container
-  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=host-single
-#  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=client-compose
-#  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=client-container
-#  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=host-single
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=client-compose
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=client-container
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=host-single
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=client-compose
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=client-container
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=host-single
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=client-compose
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=client-container
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=host-single
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=client-compose
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=client-container
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=host-single
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=client-compose
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=client-container
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=host-single
 
 before_script:
   - make test | tail