Unmount the file system on tear-down.
Unmount the file system on tear-down.

BanzaiMan/gcsfuse,GoogleCloudPlatform/gcsfuse,jacobsa/timeutil,kahing/gcsfuse,BanzaiMan/gcsfuse,jacobsa/ratelimit,mbrukman/gcsfuse,GoogleCloudPlatform/gcsfuse,GoogleCloudPlatform/gcsfuse