chore(package): update @semantic-release/git to version 9.0.0

Closes #40

Author: greenkeeper[bot]

package.json

@@ -48,7 +48,7 @@
   },
   "devDependencies": {
     "@semantic-release/changelog": "1.0.0",
-    "@semantic-release/git": "4.0.2",
+    "@semantic-release/git": "9.0.0",
     "@semantic-release/npm": "3.0.1",
     "commitplease": "3.2.0",
     "coveralls": "3.0.0",