chore(package): update semantic-release to version 15.0.0

Author: greenkeeper[bot]

package.json

@@ -34,7 +34,7 @@
     "cz-conventional-changelog": "^2.0.0",
     "nyc": "^11.1.0",
     "rimraf": "^2.6.1",
-    "semantic-release": "^12.2.2",
+    "semantic-release": "^15.0.0",
     "sinon": "^4.0.2",
     "xo": "^0.20.0"
   },