closes #57

* Automated using https://github.com/myii/ssf-formula/pull/302

* https://freenode.logbot.info/saltstack-formulas/20200506#c3811885-c3812572
* Avoid `defaults.merge`
* Send template values by `context`, to avoid:

```python
      ID: logrotate-config
Function: file.managed
    Name: /etc/logrotate.conf
  Result: False
 Comment: An exception occurred in this state: Traceback (most recent call last):
            File "/var/tmp/.root_08c4d3_salt/pyall/salt/utils/templates.py", line 394, in render_jinja_tmpl
              output = template.render(**decoded_context)
            File "/var/tmp/.root_08c4d3_salt/pyall/jinja2/environment.py", line 1008, in render
              return self.environment.handle_exception(exc_info, True)
            File "/var/tmp/.root_08c4d3_salt/pyall/jinja2/environment.py", line 780, in handle_exception
              reraise(exc_type, exc_value, tb)
            File "/var/tmp/.root_08c4d3_salt/pyall/jinja2/_compat.py", line 37, in reraise
              raise value.with_traceback(tb)
            File "<template>", line 1, in top-level template code
            File "/var/tmp/.root_08c4d3_salt/pyall/salt/utils/jinja.py", line 193, in get_source
              raise TemplateNotFound(template)
          jinja2.exceptions.TemplateNotFound: logrotate/map.jinja

          During handling of the above exception, another exception occurred:

          Traceback (most recent call last):
            File "/var/tmp/.root_08c4d3_salt/pyall/salt/state.py", line 1981, in call
              **cdata['kwargs'])
            File "/var/tmp/.root_08c4d3_salt/pyall/salt/loader.py", line 1977, in wrapper
              return f(*args, **kwargs)
            File "/var/tmp/.root_08c4d3_salt/pyall/salt/states/file.py", line 3037, in managed
              **kwargs
            File "/var/tmp/.root_08c4d3_salt/pyall/salt/modules/file.py", line 4846, in check_managed_changes
              **kwargs)
            File "/var/tmp/.root_08c4d3_salt/pyall/salt/modules/file.py", line 4287, in get_managed
              **kwargs)
            File "/var/tmp/.root_08c4d3_salt/pyall/salt/utils/templates.py", line 169, in render_tmpl
              output = render_str(tmplstr, context, tmplpath)
            File "/var/tmp/.root_08c4d3_salt/pyall/salt/utils/templates.py", line 443, in render_jinja_tmpl
              trace=tracestr)
          salt.exceptions.SaltRenderError: Jinja error: logrotate/map.jinja
          Traceback (most recent call last):
            File "/var/tmp/.root_08c4d3_salt/pyall/salt/utils/templates.py", line 394, in render_jinja_tmpl
              output = template.render(**decoded_context)
            File "/var/tmp/.root_08c4d3_salt/pyall/jinja2/environment.py", line 1008, in render
              return self.environment.handle_exception(exc_info, True)
            File "/var/tmp/.root_08c4d3_salt/pyall/jinja2/environment.py", line 780, in handle_exception
              reraise(exc_type, exc_value, tb)
            File "/var/tmp/.root_08c4d3_salt/pyall/jinja2/_compat.py", line 37, in reraise
              raise value.with_traceback(tb)
            File "<template>", line 1, in top-level template code
            File "/var/tmp/.root_08c4d3_salt/pyall/salt/utils/jinja.py", line 193, in get_source
              raise TemplateNotFound(template)
          jinja2.exceptions.TemplateNotFound: logrotate/map.jinja

          ; line 1

          ---
          {%- from "logrotate/map.jinja" import logrotate with context -%}    <======================
          {%- set config = salt['pillar.get']('logrotate:default_config', logrotate.default_config) -%}

          {%- set processed_parameters = [] -%}

          {%- macro set_parameter(parameter, default=None) -%}
          [...]
```

* Semi-automated using `ssf-formula` (v0.5.0)
* Fix errors shown below:

```bash
logrotate-formula$ $(grep "\- yamllint" .travis.yml | sed -e "s:^\s\+-\s\(.*\):\1:")
./logrotate/osmap.yaml
  1:1       warning  missing document start "---"  (document-start)

./logrotate/osfamilymap.yaml
  1:1       warning  missing document start "---"  (document-start)
  7:15      warning  truthy value should be one of [false, true]  (truthy)
  12:14     warning  truthy value should be one of [false, true]  (truthy)
  14:23     warning  truthy value should be one of [false, true]  (truthy)
  16:14     warning  truthy value should be one of [false, true]  (truthy)
  24:14     warning  truthy value should be one of [false, true]  (truthy)

./logrotate/defaults.yaml
  4:1       warning  missing document start "---"  (document-start)
  11:23     warning  truthy value should be one of [false, true]  (truthy)
  13:13     warning  truthy value should be one of [false, true]  (truthy)
  15:13     warning  truthy value should be one of [false, true]  (truthy)
  16:1      error    too many blank lines (1 > 0)  (empty-lines)

pillar.example
  3:1       warning  missing document start "---"  (document-start)
  5:4       warning  missing starting space in comment  (comments)
  6:6       warning  missing starting space in comment  (comments)
  6:5       warning  comment not indented like content  (comments-indentation)
  7:6       warning  missing starting space in comment  (comments)
  9:13      warning  truthy value should be one of [false, true]  (truthy)
  11:13     warning  truthy value should be one of [false, true]  (truthy)
  12:15     warning  truthy value should be one of [false, true]  (truthy)
  13:14     warning  truthy value should be one of [false, true]  (truthy)
  26:12     error    trailing spaces  (trailing-spaces)
  48:12     error    too many spaces after hyphen  (hyphens)
  69:1      error    too many blank lines (1 > 0)  (empty-lines)
```

This issue is causing logrotate install to fail. https://github.com/saltstack/salt/issues/51925
I've added | json to mitigate.

- Add Gentoo support
- Add FreeBSD support

Just for cosmetics

Following the template-formula example.

/var/log group in Ubuntu is syslog. This formula breaks
Ubuntu logrotate.

The iteritems dictionary method has been removed in Python 3 and using
items() is typically no problem in our case due to the fact that
dictionaries are rather small.

This fixes #15

This allows users to target this states to minions for which no pillar
has been defined (yet).

splits config file name and log file path, so you configure both.
This fixes #5.

it's crond service on fedora that initiates logrotate