Add Salt 2018.3 tests

Change-Id: I959125086475983e16c46511af212b3bbaa8df40
diff --git a/.travis.yml b/.travis.yml
index 4e7d46a..06bdbcb 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=client
-  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2016.3 SUITE=cluster
-  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2016.3 SUITE=single
-  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=client
-  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=cluster
-  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=single
-#  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=client
-#  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=cluster
-#  - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=single
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=client
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=cluster
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=single
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=client
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=cluster
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=single
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=client
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=cluster
+  - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=single
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=client
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=cluster
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=single
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=client
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=cluster
+#  - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=single
 
 before_script:
   - set -o pipefail