Add Salt 2018.3 tests

Change-Id: Idcc37252c611c37f24731bacad76c16c55fe554c
diff --git a/.travis.yml b/.travis.yml
index 7c48a82..b29e20e 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=ceph-client-single
-    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2016.3 SUITE=ceph-mon-single
-    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2016.3 SUITE=ceph-osd-single
-    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=ceph-client-single
-    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=ceph-mon-single
-    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-xenial-salt-2017.7 SUITE=ceph-osd-single
-#    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=ceph-client-single
-#    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=ceph-mon-single
-#    - PLATFORM=epcim/salt-formulas:saltstack-ubuntu-bionic-salt-2017.7 SUITE=ceph-osd-single
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=ceph-client-single
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=ceph-mon-single
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 SUITE=ceph-osd-single
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=ceph-client-single
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=ceph-mon-single
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 SUITE=ceph-osd-single
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=ceph-client-single
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=ceph-mon-single
+    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2018.3 SUITE=ceph-osd-single
+#    - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=ceph-client-single
+#    - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=ceph-mon-single
+#    - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2017.7 SUITE=ceph-osd-single
+#    - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=ceph-client-single
+#    - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=ceph-mon-single
+#    - PLATFORM=epcim/salt:saltstack-ubuntu-bionic-salt-2018.3 SUITE=ceph-osd-single
 
 before_script:
   - set -o pipefail