Change lock directory in tests to tmpfs

This prevents leftover lockfiles from interfering with tests
in between test runs.

Signed-off-by: Christina Ying Wang <christina@balena.io>

docker-compose.test.yml

@@ -20,6 +20,7 @@ services:
       - mock-systemd
     volumes:
       - dbus:/shared/dbus
+      - tmp:/mnt/root/tmp/balena-supervisor/services
       - ./test/data/root:/mnt/root
       - ./test/data/root/mnt/boot:/mnt/boot
       - ./test/lib/wait-for-it.sh:/wait-for-it.sh
@@ -71,6 +72,7 @@ services:
     stop_grace_period: 3s
     volumes:
       - dbus:/shared/dbus
+      - tmp:/mnt/root/tmp/balena-supervisor/services
     # Set required supervisor configuration variables here
     environment:
       DOCKER_HOST: tcp://docker:2375
@@ -97,8 +99,12 @@ services:
       - /mnt/data
 
 volumes:
+  # Use tmpfs to avoid files remaining between runs
   dbus:
     driver_opts:
-      # Use tmpfs to avoid files remaining between runs
+      type: tmpfs
+      device: tmpfs
+  tmp:
+    driver_opts:
       type: tmpfs
       device: tmpfs