Travis CI support

[rastersize]

As I’m on a roll right now…

I propose that Travis-CI integration is turned on for this project. This PR adds support for it (obviously also needs an owner of this repo/org to turn it on).

It uses Justin Spahr-Summers’ Objective-C build scripts to command xctool which will, when asked, build the main project and also run any unit tests.

Try it locally with ./script/cibuild.

I let the bootstrap script be left in as it then provides an explicit, compliant and future proof way of bootstrapping the project. If you feel it adds to much confusion (as the project is completely self-contained at the moment) I’ll remove it.

[rastersize]

And then I saw github/Rebel#117 which makes me wonder if the bootstrap script shouldn’t be removed or modified in this PR. I’m leaning towards modifying it and removing the explicit dependency on xctool, but then again I also want to have the bootstrap script in 😸

Edit: Relevant issue in the source repo: jspahrsummers/objc-build-scripts#5.

[indragiek]

@rastersize I think the bootstrap script is a good thing (in case we have additional steps to add later on), but the xctool dependency should be removed. @jwilling, what do you think?

[jwilling]

I'm mixed about the bootstrap script. We don't have any dependencies right now. Furthermore, I can't help but think if/when we do submodules work perfectly fine. Regardless, if you think it's useful @indragiek that's alright with me.

I definitely don't want an xctool dependency if it can be helped.

[rastersize]

@jwilling I’ve removed the dependency on xctool in the bootstrap script. The cibuild script will depend on xctool though (at least in this PR). Is that ok with you?

[indragiek]

@rastersize Thanks. However, it would be nice if we could eliminate the xctool dependency altogether. Is there a particular reason why it's necessary (even for the CI build)?