drupal#28 Restructure some code

mixins.yml

+.prepareaccess:
+  before_script:
+    - if [[ -n $SSH_PRIVATE_KEY ]]; then eval $(ssh-agent -s); fi
+    - if [[ -n $SSH_PRIVATE_KEY ]]; then echo "$SSH_PRIVATE_KEY" | tr -d '\r' | ssh-add - > /dev/null; fi
+    - if [[ -n $SSH_PRIVATE_KEY ]]; then mkdir -p ~/.ssh; fi
+    - if [[ -n $SSH_PRIVATE_KEY ]]; then chmod 700 ~/.ssh; fi
+    - if [[ -n $SSH_PRIVATE_KEY ]]; then ssh-keyscan ${GITLAB_DOMAIN} >> ~/.ssh/known_hosts; fi
+    - if [[ -n $SSH_PRIVATE_KEY ]]; then chmod 644 ~/.ssh/known_hosts; fi
+    - if [[ -n $SSH_PRIVATE_KEY ]]; then ssh git@${GITLAB_DOMAIN}; fi
+    - if [[ -n $GITLAB_ACCESS_TOKEN ]]; then composer config -g gitlab-token.${GITLAB_DOMAIN} $GITLAB_ACCESS_TOKEN; fi
+    - if [[ -n $GITLAB_PRIVATE_TOKEN ]]; then composer config -g gitlab-token.${GITLAB_DOMAIN} $GITLAB_PRIVATE_TOKEN; fi