fix(package): update @semantic-release/gitlab to version 4.0.0

BREAKING CHANGE: require GitLab version >= `11.7`

Author: greenkeeper[bot]

package.json

@@ -12,7 +12,7 @@
   ],
   "dependencies": {
     "@semantic-release/commit-analyzer": "^6.1.0",
-    "@semantic-release/gitlab": "^3.1.0",
+    "@semantic-release/gitlab": "^4.0.0",
     "@semantic-release/npm": "^5.1.1",
     "@semantic-release/release-notes-generator": "^7.1.4"
   },