Update common-env

See FGRibreau/common-env#30

Author: dsferruzza

package.json

@@ -23,7 +23,7 @@
   },
   "homepage": "https://github.com/dsferruzza/contentful2md#readme",
   "dependencies": {
-    "common-env": "^6.2.0",
+    "common-env": "^6.3.0",
     "contentful": "^7.0.5",
     "js-yaml": "^3.12.0",
     "mkdirp": "^0.5.1"