Don't require predis anymore

Author: GrahamCampbell

composer.json

@@ -13,13 +13,18 @@
         "php": "^7.1.3",
         "illuminate/contracts": "^5.5|^6.0",
         "illuminate/support": "^5.5|^6.0",
-        "illuminate/redis": "^5.5|^6.0",
-        "predis/predis": "^1.1"
+        "illuminate/redis": "^5.5|^6.0"
     },
     "require-dev": {
+        "ext-redis": "*",
         "graham-campbell/analyzer": "^2.1",
         "graham-campbell/testbench": "^5.2",
-        "phpunit/phpunit": "^6.5|^7.0|^8.0"
+        "phpunit/phpunit": "^6.5|^7.0|^8.0",
+        "predis/predis": "^1.1"
+    },
+    "suggest": {
+        "ext-redis": "Required to use the phpredis connector.",
+        "predis/predis": "Required to use the predis connector."
     },
     "autoload": {
         "psr-4": {
@@ -36,7 +41,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "5.1-dev"
+            "dev-master": "6.0-dev"
         },
         "laravel": {
             "providers": [