* Checked using https://github.com/myii/ssf-formula/pull/131

* Semi-automated using https://github.com/myii/ssf-formula/pull/40

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

```bash
syslog-ng-formula$ $(grep "\- yamllint" .travis.yml | sed -e "s:^\s\+-\s\(.*\):\1:")
./syslog_ng/defaults.yml
  4:1       warning  missing document start "---"  (document-start)

./syslog_ng/os_family_map.yml
  4:1       warning  missing document start "---"  (document-start)

./syslog_ng/os_codename_map.yml
  5:1       warning  missing document start "---"  (document-start)

pillar.example
  1:1       warning  missing document start "---"  (document-start)
  3:3       error    wrong indentation: expected 4 but found 2  (indentation)
  5:3       error    wrong indentation: expected 4 but found 2  (indentation)
  7:3       error    wrong indentation: expected 4 but found 2  (indentation)
  10:3      error    wrong indentation: expected 4 but found 2  (indentation)
  10:15     warning  truthy value should be one of [false, true]  (truthy)
  11:14     warning  truthy value should be one of [false, true]  (truthy)
  12:15     warning  truthy value should be one of [false, true]  (truthy)
  13:20     warning  truthy value should be one of [false, true]  (truthy)
  14:22     warning  truthy value should be one of [false, true]  (truthy)
  15:21     warning  truthy value should be one of [false, true]  (truthy)
  17:3      error    wrong indentation: expected 4 but found 2  (indentation)
  18:5      error    wrong indentation: expected 6 but found 4  (indentation)
  20:5      error    wrong indentation: expected 6 but found 4  (indentation)
  22:7      error    wrong indentation: expected 8 but found 6  (indentation)
  25:3      error    wrong indentation: expected 4 but found 2  (indentation)
  26:5      error    wrong indentation: expected 6 but found 4  (indentation)
  27:7      error    wrong indentation: expected 8 but found 6  (indentation)
  29:5      error    wrong indentation: expected 6 but found 4  (indentation)
  31:5      error    wrong indentation: expected 6 but found 4  (indentation)
  33:5      error    wrong indentation: expected 6 but found 4  (indentation)
  35:5      error    wrong indentation: expected 6 but found 4  (indentation)
  37:3      error    wrong indentation: expected 4 but found 2  (indentation)
  38:5      error    wrong indentation: expected 6 but found 4  (indentation)
  40:5      error    wrong indentation: expected 6 but found 4  (indentation)
  42:5      error    wrong indentation: expected 6 but found 4  (indentation)
  45:3      error    wrong indentation: expected 4 but found 2  (indentation)

pillar.debian.example
  1:1       warning  missing document start "---"  (document-start)
  3:24      warning  truthy value should be one of [false, true]  (truthy)
  5:16      warning  truthy value should be one of [false, true]  (truthy)
  6:17      warning  truthy value should be one of [false, true]  (truthy)
  15:7      error    wrong indentation: expected 8 but found 6  (indentation)
  21:7      error    wrong indentation: expected 8 but found 6  (indentation)
  24:7      error    wrong indentation: expected 8 but found 6  (indentation)
  27:7      error    wrong indentation: expected 8 but found 6  (indentation)
  30:7      error    wrong indentation: expected 8 but found 6  (indentation)
  33:7      error    wrong indentation: expected 8 but found 6  (indentation)
  36:7      error    wrong indentation: expected 8 but found 6  (indentation)
  39:7      error    wrong indentation: expected 8 but found 6  (indentation)
  42:7      error    wrong indentation: expected 8 but found 6  (indentation)
  45:7      error    wrong indentation: expected 8 but found 6  (indentation)
  50:7      error    wrong indentation: expected 8 but found 6  (indentation)
  51:9      error    wrong indentation: expected 10 but found 8  (indentation)
  53:7      error    wrong indentation: expected 8 but found 6  (indentation)
  54:9      error    wrong indentation: expected 10 but found 8  (indentation)
  56:7      error    wrong indentation: expected 8 but found 6  (indentation)
  57:9      error    wrong indentation: expected 10 but found 8  (indentation)
  61:7      error    wrong indentation: expected 8 but found 6  (indentation)
  62:9      error    wrong indentation: expected 10 but found 8  (indentation)
  64:7      error    wrong indentation: expected 8 but found 6  (indentation)
  65:9      error    wrong indentation: expected 10 but found 8  (indentation)
  67:7      error    wrong indentation: expected 8 but found 6  (indentation)
  68:9      error    wrong indentation: expected 10 but found 8  (indentation)
  72:7      error    wrong indentation: expected 8 but found 6  (indentation)
  73:9      error    wrong indentation: expected 10 but found 8  (indentation)
  75:7      error    wrong indentation: expected 8 but found 6  (indentation)
  76:9      error    wrong indentation: expected 10 but found 8  (indentation)
  78:7      error    wrong indentation: expected 8 but found 6  (indentation)
  79:9      error    wrong indentation: expected 10 but found 8  (indentation)
  83:7      error    wrong indentation: expected 8 but found 6  (indentation)
  84:9      error    wrong indentation: expected 10 but found 8  (indentation)
  88:7      error    wrong indentation: expected 8 but found 6  (indentation)
  89:9      error    wrong indentation: expected 10 but found 8  (indentation)
  93:7      error    wrong indentation: expected 8 but found 6  (indentation)
  94:9      error    wrong indentation: expected 10 but found 8  (indentation)
  98:7      error    wrong indentation: expected 8 but found 6  (indentation)
  99:9      error    wrong indentation: expected 10 but found 8  (indentation)
  103:7     error    wrong indentation: expected 8 but found 6  (indentation)
  105:7     error    wrong indentation: expected 8 but found 6  (indentation)
  107:7     error    wrong indentation: expected 8 but found 6  (indentation)
  109:7     error    wrong indentation: expected 8 but found 6  (indentation)
  111:7     error    wrong indentation: expected 8 but found 6  (indentation)
  113:7     error    wrong indentation: expected 8 but found 6  (indentation)
  115:7     error    wrong indentation: expected 8 but found 6  (indentation)
  117:7     error    wrong indentation: expected 8 but found 6  (indentation)
  120:7     error    wrong indentation: expected 8 but found 6  (indentation)
  122:7     error    wrong indentation: expected 8 but found 6  (indentation)
  125:7     error    wrong indentation: expected 8 but found 6  (indentation)
  127:7     error    wrong indentation: expected 8 but found 6  (indentation)
  129:7     error    wrong indentation: expected 8 but found 6  (indentation)
  131:7     error    wrong indentation: expected 8 but found 6  (indentation)
  133:7     error    wrong indentation: expected 8 but found 6  (indentation)
  135:7     error    wrong indentation: expected 8 but found 6  (indentation)
  135:89    error    line too long (97 > 88 characters)  (line-length)
  137:7     error    wrong indentation: expected 8 but found 6  (indentation)
  139:7     error    wrong indentation: expected 8 but found 6  (indentation)
  141:7     error    wrong indentation: expected 8 but found 6  (indentation)
  143:7     error    wrong indentation: expected 8 but found 6  (indentation)
  145:7     error    wrong indentation: expected 8 but found 6  (indentation)
  147:7     error    wrong indentation: expected 8 but found 6  (indentation)
  149:7     error    wrong indentation: expected 8 but found 6  (indentation)
  151:7     error    wrong indentation: expected 8 but found 6  (indentation)
```