Merge pull request #178 from sendinblue/feature_guzzle-update

Support guzzlehttp version update

Author: rajatsib

composer.json

@@ -22,7 +22,7 @@
         "ext-curl": "*",
         "ext-json": "*",
         "ext-mbstring": "*",
-        "guzzlehttp/guzzle": "<=7.3.0"
+        "guzzlehttp/guzzle": "^7.4.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^4.8",