fix(package): update dotenv to version 7.0.0

Author: greenkeeper[bot]

examples/multi-bot/package.json

@@ -10,7 +10,7 @@
   "dependencies": {
     "body-parser": "^1.18.3",
     "botkit": "^0.7.2",
-    "dotenv": "^6.0.0",
+    "dotenv": "^7.0.0",
     "express": "^4.16.3",
     "botkit-middleware-watson": "^1.7.1"
   }