PMPY potentially not closing files

@beausapach added additional disk to era-pmpy-prd-1, but items with large preservation packages continue to fail.

@henryzhang87 noticed

It worked for a previously failed item, but failed again for relatively large files, complaining the lack of space available, which is ODD.

I used "df -h" command to check disk usage,
[root@era-pmpy-prd-1 pushmi_pullyu]# df -h
Filesystem                               Size     Used    Avail  Use%     Mounted on
tmpfs                                        4.9G     0  4.9G   0%           /sys/fs/cgroup
/dev/mapper/system-root          248G  232G   16G   94%       /
The next step was to find out which folder has the most data usage,
[root@era-pmpy-prd-1 /]# du --exclude=./era_assets --exclude=./sys --exclude=./proc --exclude=./media --exclude=./root  --si --max-depth=1
304M    ./boot
83M     ./etc
17k     ./home
0       ./lost+found
0       ./mnt
13M     ./opt
902k    ./run
0       ./srv
566k    ./tmp
2.5G    ./usr
6.5G    ./var
13k     ./dev
9.3G    .
From the above, nothing is suspicious, only 9.3G used.

I rebooted the server, and using "df -h" again, I got:
[root@era-pmpy-prd-1 ~]# df -h
Filesystem                                 Size   Used   Avail   Use% Mounted on
/dev/mapper/system-root          248G  8.7G  239G   4%         /
That means even though the temporary files were removed from the file system, the OS still considers the removed space occupied and unavailable, unless a reboot is forced.

There are a couple of places where the files might not be closed

ualbertalib / pushmi_pullyu

PMPY potentially not closing files #475