integration-tests: config for set of integration tests for stable swarm

[nonsense]

This is the latest set of configuration files for running integration tests on Swarm, after the pushsync feature was merged.

The difference between this and the pushsync integration tests, is that these have a more limited localstore store.size and --sync-mode=all.

I suggest as next steps we:

• 1. Get rid of the --sync-mode flag altogether, prior to next release. Swarm seems to be running fine with --sync-mode=all over the last weeks.
• 2. Integrate PSS messages and counters and timers alongside the upload_and_sync cronjob smoke test. We want to have a baseline of PSS message exchange, while pushsync is running towards a given host.

Known bugs:

• 3. High value for mark/sweep timer on hosts that don't have cronjob for upload targeted at them:

Note that 1., 2. and 3. are out-of-scope for this PR, but rather suggestions for future work.

[nonsense]

To add a bit more info about the known issues/bug:

1. It appears that the mark/sweep slowness is correlated with PSS issues:

2. There were no HTTP GET requests to node swarm-private-30 at that time.

3. Goroutines on swarm-private-30 spiked to 939: