As required by changing the result version, this is a "major" version
bump. There are many changes since the last version of sbws, but we
aren't being good about recording those yet. Sorry.

to make it less confussing.
Note that stem call it ed25519_master_key instead of
master_key_ed25519, but dir-spec.txt uses master-key-ed25519, which
is the term chosen here.

Matt Traudt authored Jun 07, 2018 and juga committed Jun 10, 2018

With unused support for ed25519 keys

* RelayList is now a list of RelayNS instead of RouterStatusEntryV3
  to have master_key_ed25519 as an attribute
* create pytest fixture to start Tor with tests
* create test to check master_key_ed25519

* Move logic in generate to class
* Add test
* Move 7500 to global constant
* Make read_started_at not fail when conf is None

    * Move V3BWLine to v3bwfile.py
    * Add methods to V3BWLine similar to V3BwHeader
    * Add methods to V3BWLine to implement most of the logic in the class
    * Move functions related to data lines to v3bwfile.py
    * Add functions to generate types of erros
    * Add tests for the class and conftest to read results from file
    * Fix other tests depending on bw lines

also:
* remove latest_bandwidth outside of class, since it should be
  generated from timestamp
* pass all init arguments as string
* require timestamp argument
* fix tests with changes

they do not need to be in 3rd and 4th posstions.

Also:
* add latest_bandwidth header
* add file_created header
* fix bw files header tests
* disable tests that assume timestamp to be the file creation
time
* if we use ISO 8601 with T as separator,
  datetime format string is not needed