Fix broken circle build (#351)

Signed-off-by: David Chung <david.chung@docker.com>

Author: David Chung

circle.yml

@@ -9,6 +9,7 @@ machine:
     GOVERSION: "1.7"
     GOPATH: "$HOME/.go_workspace"
     WORKDIR: "$GOPATH/src/github.com/$CIRCLE_PROJECT_USERNAME/$CIRCLE_PROJECT_REPONAME"
+    DOCKER_RM: "false"
 
 dependencies:
   pre:

scripts/container-test

@@ -10,10 +10,14 @@ cd "$HERE/.."
 TEST_DIR=$(pwd)/container-test
 DOCKER_IMAGE="${DOCKER_IMAGE:-infrakit/devbundle}"
 DOCKER_TAG="${DOCKER_TAG:-dev}"
+DOCKER_RM="${DOCKER_RM:-true}"
 
 cleanup() {
-  docker ps | grep devbundle | awk '{print $1}' | xargs docker stop
-  docker ps | grep devbundle | awk '{print $1}' | xargs docker rm
+  if [ "$DOCKER_RM" = "true" ]; then
+    echo "cleaning up docker images"
+    docker ps | grep devbundle | awk '{print $1}' | xargs docker stop
+    docker ps | grep devbundle | awk '{print $1}' | xargs docker rm
+  fi
   rm -rf $TEST_DIR
 }
 trap cleanup EXIT