bump verison to 4.0.7 (#181)

Author: coaldonac

package-lock.json

@@ -9,7 +9,7 @@
     "sending",
     "transactional"
   ],
-  "version": "4.0.6",
+  "version": "4.0.7",
   "author": "Postmark (under ActiveCampaign LLC)",
   "contributors": [
     "Igor Balos",