* add yamllint command to travis CI
installs and runs a linter across the YAML in the
project to ensure consistency in the written YAML.
this uses yamllint and the default yamllint config with
"truthy" and "line-length" disabled.
* run dos2unix on CRLF files
* YAMLLINT: remove trailing spaces
* YAMLLint: add YAML document start
* YAMLLint: too many spaces around bracket
* YAMLLint: fix indentation
* YAMLLint: remove duplicate key
* YAMLLint: newline at end of file
* YAMLLint: Too few spaces after comma
* YAMLLint: too many spaces after colon
