Update Twilio SDK version

Author: gregoriohc

composer.json

@@ -13,7 +13,7 @@
     ],
     "require": {
         "php": ">=5.5.9",
-        "twilio/sdk": "^5.4.1",
+        "twilio/sdk": "~5.16",
         "illuminate/notifications": "5.1.*|5.2.*|5.3.*|5.4.*|5.5.*|5.6.*",
         "illuminate/support": "5.1.*|5.2.*|5.3.*|5.4.*|5.5.*|5.6.*",
         "illuminate/events": "5.1.*|5.2.*|5.3.*|5.4.*|5.5.*|5.6.*",