Pool and server configuration may have different options but it's not
currently possible.
In order to solve that, the template is changed to accept pool
or server specification as a dictionnary, specifying at least the
pool/server name and if wanted the pool/server options. If no options
are specified, it'll use chrony.options.
In order to not break anything the template is checking if the server/pool
specification is a dictionnary or not, and acts accordingly.

Fixes: #27
Signed-off-by: Arnaud Patard <apatard@hupstream.com>

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

```bash
chrony-formula$ $(grep "\- yamllint" .travis.yml | sed -e "s:^\s\+-\s\(.*\):\1:")
pillar.example
  1:1       warning  missing document start "---"  (document-start)
  21:3      warning  comment not indented like content  (comments-indentation)
```

BREAKING CHANGE: `chrony.removed` replaced by `.clean` states.