chore: drop support for php 5.5 (#5409)

.github/workflows/tests.yaml

@@ -16,10 +16,6 @@ jobs:
         phpunit-filename: [phpunit]
         grpc-version: [grpc]
         include:
-          - platform: ubuntu-latest
-            php: "5.5"
-            phpunit-filename: phpunit-php5
-            grpc-version: grpc-1.33.1
           - platform: ubuntu-latest
             php: "5.6"
             phpunit-filename: phpunit-php5

CONTRIBUTING.md

@@ -18,7 +18,7 @@ You can sign these electronically (just scroll to the bottom). After that, we'll
 In order to use Google Cloud PHP, some setup is required!
 
 1. Install PHP.
-    Google Cloud PHP requires PHP 5.5 or higher. Installation of PHP varies depending on your system. Refer to the [PHP installation and configuration documentation](http://php.net/manual/en/install.php) for detailed instructions.
+    Google Cloud PHP requires PHP 5.6 or higher. Installation of PHP varies depending on your system. Refer to the [PHP installation and configuration documentation](http://php.net/manual/en/install.php) for detailed instructions.
 
 2. Install [Composer](https://getcomposer.org/download/).
 

Core/composer.json

@@ -4,7 +4,7 @@
     "license": "Apache-2.0",
     "minimum-stability": "stable",
     "require": {
-        "php": ">=5.5",
+        "php": ">=5.6",
         "rize/uri-template": "~0.3",
         "google/auth": "^1.18",
         "guzzlehttp/guzzle": "^5.3|^6.5.7|^7.4.4",

README.md

@@ -176,7 +176,7 @@ $spanner = new SpannerClient([
 
 ## PHP Versions Supported
 
-All client libraries support PHP 5.5 and above, with the exception of
+All client libraries support PHP 5.6 and above, with the exception of
 [Google Cloud Compute](Compute), which supports PHP 7.0 and above.
 
 ## Versioning

composer.json

@@ -43,7 +43,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5",
+        "php": ">=5.6",
         "rize/uri-template": "~0.3",
         "guzzlehttp/guzzle": "^5.3|^6.5.7|^7.4.4",
         "guzzlehttp/psr7": "^1.7|^2.0",