fix(package): update dotenv to version 6.2.0

Closes #8

Author: greenkeeper[bot]

package.json

@@ -6,7 +6,7 @@
   "dependencies": {
     "bcryptjs": "^2.4.3",
     "body-parser": "^1.18.2",
-    "dotenv": "^5.0.0",
+    "dotenv": "^6.2.0",
     "express": "^4.16.2",
     "install": "^0.11.0",
     "jsonwebtoken": "^8.1.1",