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

Closes #34

Author: greenkeeper[bot]

package.json

@@ -81,7 +81,7 @@
     "react-addons-test-utils": "^15.4.1",
     "react-dom": "^15.4.1",
     "rimraf": "^2.5.3",
-    "semantic-release": "^6.3.2",
+    "semantic-release": "^15.0.0",
     "sinon": "^2.2.0"
   }
 }