Add tmpfs for test mysql instances

.drone1.yml

@@ -5,17 +5,31 @@ workspace:
   base: /go
   path: src/code.vikunja.io/api
 
+volumes:
+  - name: tmp-mysql-unit
+    temp:
+      medium: memory
+  - name: tmp-mysql-integration
+    temp:
+      medium: memory
+
 services:
   - name: test-mysql-unit
     image: mariadb:10
     environment:
       MYSQL_ROOT_PASSWORD: vikunjatest
       MYSQL_DATABASE: vikunjatest
+    volumes:
+      - name: tmp-mysql-unit
+        path: /var/lib/mysql
   - name: test-mysql-integration
     image: mariadb:10
     environment:
       MYSQL_ROOT_PASSWORD: vikunjatest
       MYSQL_DATABASE: vikunjatest
+    volumes:
+      - name: tmp-mysql-integration
+        path: /var/lib/mysql
   - name: test-mysql-migration
     image: mariadb:10
     environment: