Remove salt-2016 from .travis.yml

Change-Id: I5e6a8e1e35a635816e8ff3082104a35bb9b58302
diff --git a/.travis.yml b/.travis.yml
index 7c03c2b..ac14c86 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,17 +15,6 @@
   - bundle install
 
 env:
-    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 OS_VERSION=mitaka SUITE=ceph-single
-    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 OS_VERSION=mitaka SUITE=control-cluster
-    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 OS_VERSION=mitaka SUITE=control-single
-    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 OS_VERSION=mitaka SUITE=gpfs-single
-    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 OS_VERSION=mitaka SUITE=hp3par-single
-    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 OS_VERSION=mitaka SUITE=lefthand-single
-    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 OS_VERSION=mitaka SUITE=solidfire-single
-    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 OS_VERSION=mitaka SUITE=storwize-single
-    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 OS_VERSION=mitaka SUITE=volume-single
-    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 OS_VERSION=mitaka SUITE=vsp-single
-    - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2016.3 OS_VERSION=mitaka SUITE=volume-single-barbican
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 OS_VERSION=ocata SUITE=ceph-single
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 OS_VERSION=ocata SUITE=control-cluster
     - PLATFORM=epcim/salt:saltstack-ubuntu-xenial-salt-2017.7 OS_VERSION=ocata SUITE=control-single