Investigate whether tusd is leaking resouces

[Acconut]

The entries at http://master.tus.io/metrics might indicate that tusd is leaking file descriptors and/or goroutines. This is just an idea but these number could be a hint:

# HELP go_goroutines Number of goroutines that currently exist.
# TYPE go_goroutines gauge
go_goroutines 13

# HELP go_threads Number of OS threads created.
# TYPE go_threads gauge
go_threads 21

# HELP process_open_fds Number of open file descriptors.
# TYPE process_open_fds gauge
process_open_fds 9

# HELP tusd_connections_open Current number of open connections.
# TYPE tusd_connections_open gauge
tusd_connections_open 1