Use tmpfs for mysql CI containers

Should improve performance

Signed-off-by: Morris Jobke <hey@morrisjobke.de>

.drone.yml

@@ -650,6 +650,8 @@ services:
     environment:
       - POSTGRES_USER=oc_autotest
       - POSTGRES_PASSWORD=owncloud
+    tmpfs:
+      - /var/lib/postgresql/data
     when:
       matrix:
         DB: postgres
@@ -660,6 +662,8 @@ services:
       - MYSQL_USER=oc_autotest
       - MYSQL_PASSWORD=owncloud
       - MYSQL_DATABASE=oc_autotest
+    tmpfs:
+      - /var/lib/mysql
     when:
       matrix:
         DB: mysql
@@ -671,6 +675,8 @@ services:
       - MYSQL_PASSWORD=owncloud
       - MYSQL_DATABASE=oc_autotest
     command: [ "--innodb_large_prefix=true", "--innodb_file_format=barracuda", "--innodb_file_per_table=true" ]
+    tmpfs:
+      - /var/lib/mysql
     when:
       matrix:
         DB: mysqlmb4