[#1] We don't need set -ex for idempotence test

.gitlab-ci.yml

+image: alpine:3.7
+
+cache:
+  key: ${CI_COMMIT_REF_SLUG}
+
+stages:
+- test
+
+variables:
+  MIRROR_VALUES_FILE: mirror-values.yml
+
+centos7_test_install:
+  stage: test
+  image: centos:centos7
+  before_script:
+  - |
+    yum -y update && yum -y install ansible
+    echo "localhost" > tests/inventory
+    mkdir -p tests/roles
+    ln -s $(pwd) tests/roles/nagios-nrpe-agent
+  after_script:
+  - rm -rf tests/roles
+  - rm -f $MIRROR_VALUES_FILE
+  script:
+  - |
+    echo -e "mirror_hostname: ${mirrorHostname}\nmirror_path: ${mirrorPath}\nmirror_protocol: ${mirrorProtocol}\n" > $MIRROR_VALUES_FILE
+    set -ex
+    # Basic role syntax check
+    ansible-playbook --list-hosts tests/test-playbook.yml --inventory tests/inventory --connection local
+    ansible-playbook tests/test-playbook.yml --inventory tests/inventory --syntax-check
+
+    # Run the first time
+    ansible-playbook tests/test-playbook.yml --inventory tests/inventory --connection local --extra-vars @${MIRROR_VALUES_FILE}
+
+  - >
+    ansible-playbook tests/test-playbook.yml --inventory tests/inventory --connection local --extra-vars @${MIRROR_VALUES_FILE}
+    | grep -q 'changed=0.*failed=0'
+    && (echo 'Idempotence test: pass' && exit 0)
+    || (echo 'Idempotence test: fail' && exit 1)
+