Merge pull request #138 from cbj4074/patch-1

Re-add upper bound on twilio/sdk version constraint

Author: hannesvdvreken

composer.json

@@ -17,7 +17,7 @@
     "license": "MIT",
     "require": {
         "php": ">=5.5.0",
-        "twilio/sdk":">=3.12.0"
+        "twilio/sdk":">=3.12.0,<5.0.0"
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^1.9",