build: use PHP for release-docker script

package.json

@@ -4,7 +4,7 @@
   "private": true,
   "scripts": {
     "commitmsg": "validate-commit-msg",
-    "semantic-release": "semantic-release pre && ./release-docker.sh && semantic-release post"
+    "semantic-release": "semantic-release pre && php release-docker.php && semantic-release post"
   },
   "devDependencies": {
     "cz-conventional-changelog": "^2.0.0",

release-docker.php

@@ -0,0 +1,10 @@
+<?php
+
+$dockerEmail = getenv('DOCKER_EMAIL');
+$dockerUsername = getenv('DOCKER_USERNAME');
+$dockerPassword = getenv('DOCKER_PASSWORD');
+$version = json_decode(file_get_contents(__DIR__ . '/package.json'))->version;
+
+system("docker login -e=$dockerEmail -u=$dockerEmail -p=$dockerPassword");
+system("docker build -t felixfbecker/php-language-server:$version .");
+system("docker push felixfbecker/php-language-server:$version");