Remove EL6 testing from Travis (puppetlabs#165)

Author: carabasdaniel

.sync.yml

@@ -15,7 +15,6 @@
     provision_list:
       - travis_deb
       - travis_ub
-      - travis_el6
       - travis_el7
       - travis_el8
       - ---travis_el

.travis.yml

@@ -49,17 +49,6 @@ jobs:
       script: ["travis_wait 45 bundle exec rake litmus:acceptance:parallel"]
       services: docker
       stage: acceptance
-    -
-      before_script:
-      - "bundle exec rake 'litmus:provision_list[travis_el6]'"
-      - "bundle exec rake 'litmus:install_agent[puppet5]'"
-      - "bundle exec rake litmus:install_module"
-      bundler_args:
-      env: PLATFORMS=travis_el6_puppet5
-      rvm: 2.5.7
-      script: ["travis_wait 45 bundle exec rake litmus:acceptance:parallel"]
-      services: docker
-      stage: acceptance
     -
       before_script:
       - "bundle exec rake 'litmus:provision_list[travis_el7]'"
@@ -104,17 +93,6 @@ jobs:
       script: ["travis_wait 45 bundle exec rake litmus:acceptance:parallel"]
       services: docker
       stage: acceptance
-    -
-      before_script:
-      - "bundle exec rake 'litmus:provision_list[travis_el6]'"
-      - "bundle exec rake 'litmus:install_agent[puppet6]'"
-      - "bundle exec rake litmus:install_module"
-      bundler_args:
-      env: PLATFORMS=travis_el6_puppet6
-      rvm: 2.5.7
-      script: ["travis_wait 45 bundle exec rake litmus:acceptance:parallel"]
-      services: docker
-      stage: acceptance
     -
       before_script:
       - "bundle exec rake 'litmus:provision_list[travis_el7]'"

provision.yaml

@@ -20,12 +20,6 @@ travis_ub:
   - litmusimage/ubuntu:14.04
   - litmusimage/ubuntu:16.04
   - litmusimage/ubuntu:18.04
-travis_el6:
-  provisioner: docker
-  images:
-  - litmusimage/centos:6
-  - litmusimage/oraclelinux:6
-  - litmusimage/scientificlinux:6
 travis_el7:
   provisioner: docker
   images: