fix: added mariadb service to gh actions

Author: d4rpx1

.github/workflows/gradle.yml

@@ -41,6 +41,16 @@ jobs:
 
     runs-on: ubuntu-18.04
 
+    services:
+      mariadb:
+        image: mariadb:latest
+        ports:
+          - 3306
+        env:
+          MYSQL_DATABASE: matrix
+          MYSQL_ROOT_PASSWORD: root
+        options: --health-cmd="mysqladmin ping" --health-interval=5s --health-timeout=2s --health-retries=3
+
     steps:
       - name: Set up JDK 17
         uses: actions/setup-java@v1