Add travis

[lislis]

Hey @una!

I took the liberty to add a .travis.yml mentioned in this issue #168

The current configuration runs gulp lib-scss and gulp sass-lint on Node versions 4, 5 and 6.
Let me know if you need these configurations changed.

I'd also add a Gulp task that builds the site but doesn't use browser sync/ opens a browser. wdyt?

[una]

the start script is just gulp for building the site out -- whats the benefit of Travis here?

[lislis]

Hey @una and sorry for the delayed reply!
The command gulp builds the site and tries to open/ sync a browser (If I read the Gulpfile correctly). We can't exactly do that in Travis.
But we can test if the scss builds (or the twig templates for that matter) to detect errors without checking the page locally.
Is that something you'd be interested in having at all? I figured I just start somewhere after I saw the open ticket. But if you don't feel free to just close the PR :)

[una]

Yeah definitely, I'm just trying to get some more context and learn a bit more about it 😄 I think this is definitely a good idea!

[lislis]

Let me know if you need more information. I can also add some comments if that helps :)

[una]

Why is sudo required here?

[lislis]

Good question! The Travis docs state that to compile NodeJS v4 or later a newer C++ compiler is needed.
That compiler is currently available in images that also allow sudo rights in your build.
So while we don't need sudo explicitly we need the build image that offers it.
Does that make sense?