Use bytes to compare the sum of scaled bandwidth (in KB) with the
sum of the consensus one (previously converted to Bytes measured.
Also:
- Check that the bandwidth attribute exists, since it was not
  stored in older versions.
- Do not sum the bw=1 as a result of the relays being unmeasured.
- Calculate the percentage difference as two difference values.
- Log which were actually the bandwidth sums.

when setting vote and unmeasured Keys.
It doesn't matter here because there're not operations with the
Keys and they're always converted to string in the bandwidth file,
but it less confusing as integer.

to test that the `under_min_report` KeyValue is added when the
number of eligible relays is less than the 60% of relays in the
consensus.

and run generate as part of the integration tests.
This allows to later check that the testnet genearted files
contain the expected Keys and Values with an script in #29727.

even if the minimum percent was not reach.

Closes: #29853.

under_min_report KeyValue when the minimum percent is not reached.
Also change list by int the methods that calculate the progress.

Part of #29853.

in the Bandwidth Lines.
When the minimum percent of relays it's not reached, still report
the relays but set KeyValues accordingly so that Tor doesn't vote
on their bandwidth.

Part of #29853.

in the Bandwidth Lines.

Part of #29853.

since Travis is failing to check github.com with forbidden error,
but it doesn't fail locally
(https://travis-ci.org/torproject/sbws/jobs/511862070#L1938).

and move contributing from the root directory to the docs/ one,
since it links to testing but testing is not in the root directory.
This way when a user only reads the readme locally, does not try
to find testing in the root directory and instead will search for
more documentation in docs/.

Since when a destination fails, all the threads using it will also
fail that moment.
For now not checking which threads are actually using it.
Also lower the time to retry.

Closes: #29891.

calling requests.get, since RequestException does not catch all.

The number of prioritized relays was set to the minimum, but in a
small testing network this could be lesser than the number of
relays in the network.

measuring unique relays.
Create new module heartbeat.

Closes: #28652

There was an ammended commit diverging from canonical master

Conflicts:
	sbws/lib/v3bwfile.py
	tests/unit/lib/test_v3bwfile.py

in the bandwidth file to know why there excluded relays.
The excluded relays' lines do not have the `bw` KeyValue so that
Tor does not parse them nor include them in a vote.

Closes: #28563

to the bandwidth file header.

Closes: #28983.

and improve a bit the summary about what sbws does.
Closes: #29722

Part of #28565.

Part of #28565.

and return reason why the relay was excluded to be able to count
the relays excluded in the header.
Part of #28565.

Part of #28565.

if sbws is shutting down.

for the maximum number of failures before the destination is
not functional.

Part of #29589.

Closes: #29589.

Part of #29589.