Test documentation

[ElectricMaxxx]

We should implement a linter and a build test for docs. Escpecially when i start edititng the rst stuff, there are plenty options to break the docs.

[kunicmarko20]

So, with current travis configuration, I do not think there can be a clean solution for this. (or I am not aware of one)

https://github.com/FriendsOfSymfony/FOSCKEditorBundle/blob/e02ec3868533d0759c5595da8a147b5e2c4df9f2/.travis.yml#L50-L54

This will always run, so if we add docs tests, we would also run phpunit tests, my suggestion is we reverty to custom travis folder with scripts, like it had been before, we also do it in sonata that way:

https://github.com/sonata-project/SonataAdminBundle/blob/3.x/.travis.yml

  include:
    - php: '7.2'
      env: TARGET=docs

install:
  - if [ -x .travis/install_${TARGET}.sh ]; then .travis/install_${TARGET}.sh; fi;

before_script:
  - if [ -x .travis/before_script_${TARGET}.sh ]; then .travis/before_script_${TARGET}.sh; fi;

and then we have a folder with scripts: https://github.com/sonata-project/SonataAdminBundle/tree/3.x/.travis

[ElectricMaxxx]

Mhh. @stof maybe knows how to handle doc building tests in. a travis cinfig accepting best practices?

[kunicmarko20]

I already provided PR to go back to scripts, we can wait for @stof and see if he knows, if not, I have ready a follow-up PR that will add docs test.