This PR introduces the following fixes:
- Fixes a race condition by protecting the `scheduledQueries` and
`scheduledQueryData` fields with a `sync.Mutex` (*).
- Adds some more information about request counts for /log, /config and
/distributed/read requests (and uptime).
- Fixes the resource leaks around creating time.Ticks on every for loop
iteration.
(*) Sample of the race condition when running with `-race`:
```
==================
WARNING: DATA RACE
Read at 0x00c000604800 by goroutine 20:
main.(*agent).runLoop()
/Users/luk/fleetdm/git/fleet/cmd/osquery-perf/agent.go:525 +0x71b
main.main.func2()
/Users/luk/fleetdm/git/fleet/cmd/osquery-perf/agent.go:1737 +0x4e
Previous write at 0x00c000604800 by goroutine 40:
main.(*agent).config()
/Users/luk/fleetdm/git/fleet/cmd/osquery-perf/agent.go:915 +0xb30
main.(*agent).runLoop.func2()
/Users/luk/fleetdm/git/fleet/cmd/osquery-perf/agent.go:512 +0x37
```
Lucas Manuel Rodriguez
5d7ee58a87