chore(package): update @semantic-release/npm to version 5.1.2

Closes #25

Author: greenkeeper[bot]

package.json

@@ -28,7 +28,7 @@
     "@semantic-release/changelog": "^2.0.1",
     "@semantic-release/git": "^4.0.1",
     "@semantic-release/github": "^4.2.7",
-    "@semantic-release/npm": "^3.2.2",
+    "@semantic-release/npm": "^5.1.2",
     "commitizen": "^2.9.6",
     "cz-conventional-changelog": "^2.1.0",
     "husky": "^0.14.3",