chore: clean Babel configs (#24)

- avoid using stage-0
- remove deprecated preset-latest in favor of preset-env

packages/xo-server-load-balancer/package.json

@@ -39,8 +39,7 @@
     "babel-cli": "^6.24.1",
     "babel-plugin-lodash": "^3.3.2",
     "babel-plugin-transform-runtime": "^6.23.0",
-    "babel-preset-es2015": "^6.24.1",
-    "babel-preset-stage-0": "^6.24.1",
+    "babel-preset-stage-3": "^6.24.1",
     "dependency-check": "^2.9.1"
   },
   "scripts": {
@@ -56,8 +55,15 @@
       "lodash"
     ],
     "presets": [
-      "es2015",
-      "stage-0"
+      [
+        "env",
+        {
+          "targets": {
+            "node": 4
+          }
+        }
+      ],
+      "stage-3"
     ]
   }
 }

packages/xo-server-load-balancer/src/index.js

@@ -133,7 +133,7 @@ const makeJob = (cronPattern, fn) => {
 class LoadBalancerPlugin {
   constructor (xo) {
     this.xo = xo
-    this._job = makeJob(`*/${EXECUTION_DELAY} * * * *`, ::this._executePlans)
+    this._job = makeJob(`*/${EXECUTION_DELAY} * * * *`, this._executePlans.bind(this))
   }
 
   async configure ({ plans }) {