Set DOCKER_API_VERSION in DOCKER_DOWNGRADE

.travis.yml

@@ -13,9 +13,18 @@ cache:
   directories:
     - downloads
 
-env:
-  - DOCKER_DOWNGRADE="echo nothing to be done"
-  - DOCKER_API_VERSION="1.24" DOCKER_DOWNGRADE="docker save -o images.tar mqadvanced-server-dev mq-dev-jms-test && sudo apt-get autoremove -y docker-ce && curl -fsSL \"https://apt.dockerproject.org/gpg\" | sudo apt-key add - && sudo apt-add-repository \"deb https://apt.dockerproject.org/repo ubuntu-$(lsb_release -cs) main\" && sudo apt-get update && sudo apt-get install docker-engine=1.12.6-0~ubuntu-$(lsb_release -cs) && docker load -q -i mqadvanced-server-dev.tar"
+jobs:
+  include:
+    - if: type IN (pull_request)
+      env: DOCKER_DOWNGRADE="docker save -o images.tar mqadvanced-server-dev mq-dev-jms-test &&
+        sudo apt-get autoremove -y docker-ce &&
+        curl -fsSL \"https://apt.dockerproject.org/gpg\" | sudo apt-key add - &&
+        sudo apt-add-repository \"deb https://apt.dockerproject.org/repo ubuntu-$(lsb_release -cs) main\" &&
+        sudo apt-get update &&
+        sudo apt-get install docker-engine=1.12.6-0~ubuntu-$(lsb_release -cs) &&
+        docker load -q -i mqadvanced-server-dev.tar &&
+        export DOCKER_API_VERSION=\"1.24\""
+    - env: DOCKER_DOWNGRADE="echo nothing to be done"
 
 before_install:
   - curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -