Add Salt 2018.3 tests

Change-Id: Ic22102fccf7beb0674b809262c324b791102f43a
diff --git a/.travis.yml b/.travis.yml
index cf42815..b28c3a9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -17,15 +17,21 @@
   - bundle install
 
 env:
-    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2016.3 SUITE=network
-    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2016.3 SUITE=pool
-    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2016.3 SUITE=simple
-    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=network
-    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=pool
-    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=simple
-    # - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=network
-    # - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=pool
-    # - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=simple
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=network
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=pool
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=simple
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=network
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=pool
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=simple
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=network
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=pool
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=simple
+    # - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=network
+    # - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=pool
+    # - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=simple
+    # - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=network
+    # - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=pool
+    # - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=simple
 
 before_script:
   - set -o pipefail