reading from the file created in the same test

**Important changes**:

- The way users configure logging has changed. No longer are most users
  expected to be familiar with how to configure python's standard logging
library with a config file. Instead we've abstracted out the setting of log
level, format, and destinations to make these settings more accessible to
users. Expert users familiar with [the logging config file format][logconffmt]
can still make tweaks.

Summary of changes:

- Make logging configuration easier for the user.
- Add UML diagrams to documentation. They can be found in docs/source/images/
  and regenerated with `make umlsvg` in docs/.

[logconffmt]: https://docs.python.org/3/library/logging.config.html#logging-config-fileformat

Since sbws migth be run as a system service, it should give some
information to the system log.
There are no new options to configure for the user, and it's
disabled by default.

and call it from object instance, otherwise generate would fail.
write method should not be a classinstance since a Class won't
have useful information to write, and can't be an static method
since it requires an argument.

and add a simple first sentence about what this program does.

GH: ref #201