chore(package): update @semantic-release/github to version 6.0.2

Closes #44

Author: greenkeeper[bot]

package.json

@@ -40,7 +40,7 @@
     "@semantic-release/commit-analyzer": "^6.1.0",
     "@semantic-release/exec": "^3.3.2",
     "@semantic-release/git": "^7.0.8",
-    "@semantic-release/github": "^5.2.10",
+    "@semantic-release/github": "^6.0.2",
     "@semantic-release/release-notes-generator": "^7.1.4",
     "broccoli-asset-rev": "^3.0.0",
     "bulma": "^0.7.4",