.yamllint

* Semi-automated using https://github.com/myii/ssf-formula/pull/27
* Fix (or ignore) errors shown below:

```bash
mysql-formula$ yamllint -s .
./mysql/osfamilymap.yaml
  46:14     error    empty value in block mapping  (empty-values)
  66:14     error    empty value in block mapping  (empty-values)
  67:14     error    empty value in block mapping  (empty-values)
  68:16     error    empty value in block mapping  (empty-values)
  69:17     error    empty value in block mapping  (empty-values)
  70:16     error    empty value in block mapping  (empty-values)
  87:7      error    empty value in block mapping  (empty-values)
  216:14    error    empty value in block mapping  (empty-values)
  217:17    error    empty value in block mapping  (empty-values)

./mysql/defaults.yaml
  29:10     error    empty value in block mapping  (empty-values)
  30:11     error    empty value in block mapping  (empty-values)
```