Draft: Resolve #3283651 "Guzzle6 adapter"

Closes #3283651

composer.json

 {
     "name": "drupal/geocoder",
-    "description": "A Drupal module and a services based API to perform Geocode & Reverse Geocode operations among GIS data and addresses types & formats.",
+    "description": "Module and services based API to perform Geocode & Reverse Geocode operations among GIS data and addresses types & formats.",
     "type": "drupal-module",
     "license": "GPL-2.0-or-later",
     "minimum-stability": "dev",
@@ -25,7 +25,6 @@
     },
     "require": {
         "php": ">=7.1.0",
-        "php-http/guzzle6-adapter": "^1.1 || ^2.0",
         "php-http/message": "^1.6",
         "willdurand/geocoder": "^4.0",
         "davedevelopment/stiphle": "^0.9.2"