Update .gitlab-ci.yml to install apache packages

required by mod_wsgi

Former-commit-id: eea386bd0e28117fb7dfe148994191b054427622

.gitlab-ci.yml

@@ -8,6 +8,7 @@ test-centos7:
   - yum install -y epel-release
   - yum install install -y python34-pip python34-devel
   - yum install -y gcc graphviz graphviz-devel
+  - yum install -y httpd httpd-devel
   - cd ippisite
   - pip3 install -r requirements.txt
   - python3 manage.py test