check markdown in travis build

[thijstriemstra]

No description provided.

[thijstriemstra]

@FooDeas the default base branch is master when you open a pull request, I think that should change to devel because I now have to change it manually.

[FooDeas]

Default branch is changed to devel.

[thijstriemstra]

Do we really need the exclusions of shellcheck and markdown rules?

Think so @FooDeas, try running them without (line-length then has to be < 80 triggering many errors for example and I found other errors not useful). The ~ means they're excluded for mdl.

[FooDeas]

I see! Then I suggest the following .travis.yml config:

language: bash
install: gem install mdl
script:
 - bash -c 'shopt -s globstar; shellcheck **/*.sh'
 - mdl -r '~MD013, ~MD036' .

I'd like to fix the docs for MD013 and MD036 piece by piece.

[thijstriemstra]

@FooDeas changed it but expecting the build to fail now. Feel free to fix these in this branch or elsewhere.