Feat local test container for windows + conteiner for js and python unit tests

[poWer4aiX]

Support to

• run the python and javascript unit tests in a docker container as well
• run all the tests in docker containers on Windows.

This PR fixes #236.

[poWer4aiX]

@timdegroot1996 I'm currently working on updating the documentation to cover the usage under Linux and Windows.

[timdegroot1996]

@poWer4aiX, as you can see I made 3 small commits that fixed it locally for me. I had to add the discussed .gitattributes, and the typos and \ had to be changed to work correctly on my machine. Apart from that I think we can merge this unless you have any final thoughts regarding these changes.

Let me know!

PS: It is very nice to run it like this, so thanks a lot for contributing towards this! 👍

[poWer4aiX]

@timdegroot1996, oh I missed to add the .gitattributes you proposed before, sorry for that. The fix to escape the $ in the script is absolutely correct. For some reason this caused not any issues in my setup with the git bash on my windows laptop.

From my point of view, we are ready to merge. And thanks for all the work you spend to create robotframework-dashboard!