chore(package): update semantic-release to version 15.0.1

Closes #63

Author: greenkeeper[bot]

package.json

@@ -26,7 +26,7 @@
     "condition-circle": "^1.5.0",
     "grimoirejs": "^0.19.5",
     "grimoirejs-cauldron": "^3.1.6",
-    "semantic-release": "^7.0.2",
+    "semantic-release": "^15.0.1",
     "ts-loader": "^2.3.3",
     "typedoc": "^0.8.0",
     "typescript": "^2.4.2",