composer.json: Upgrade knplabs/github-api

#1158

Author: reedy

composer.json

@@ -11,7 +11,9 @@
         "ext-mbstring": "*",
         "ext-pdo": "*",
         "ext-simplexml": "*",
-        "knplabs/github-api": "^1.4"
+        "guzzlehttp/guzzle": "^7.0.1",
+        "http-interop/http-factory-guzzle": "^1.0",
+        "knplabs/github-api": "^3.0"
     },
     "require-dev": {
         "php-parallel-lint/php-parallel-lint": "^1.3.2",