The following source -- although not loadable by pyyaml -- is valid
YAML:
{{key}}: value
This was processed badly by yamllint. The same for `[[value]]`,
`{{{{{moustaches}}}}}` or:
{[val,
{{key: val,
key2}}]}
This patch corrects it and add corresponding test cases.
Related-to: #3
76f47e91ca