fix(package): update simple-git to version 2.3.0

Closes #22

Author: greenkeeper[bot]

package.json

@@ -40,7 +40,7 @@
     "fs-extra": "^8.1.0",
     "nodesfc": "^0.7.2",
     "queue": "^6.0.1",
-    "simple-git": "^1.124.0",
+    "simple-git": "^2.3.0",
     "socket.io-client": "^2.2.0",
     "tmp": "^0.2.0",
     "update-notifier": "^4.1.0"