Remove digger setup and use the compiler from Travis

[wilzbach]

Digger was added to be able to test tools with the latest DMD.
So Digger builds the latest dmd, druntime and phobos and we have enabled a daily cron here that checks every day that things are still working.
However, now that we have the Project Tester we can simply add dlang/tools to it and thus be on the safe side as the testsuite is now run on every PR.

The respective dlang/ci PR is: dlang/ci#130

[dlang-bot]

Thanks for your pull request, @wilzbach!

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[WebDrake]

I think it might be a good idea to tie down test requirements of #297 before making changes like this. Unless there are other reasons motivating these changes I would suggest putting them on hold (likewise the CI PR).

[wilzbach]

I think it might be a good idea to tie down test requirements of #297 before making changes like this.

Fair enough - it's not passing Travis anyways at the moment.

I would suggest putting them on hold (likewise the CI PR).

I don't agree about the CI PR. It's a requirement that dlang/tools is always buildable with latest, greatest master. This requirement will never change. All dlang/ci does is to execute the travis.sh, so we are pretty flexible, but if changes are needed this can be easily overwritten to manually execute the Makefile with dmd only.
OTOH this hasn't been done for a couple of months, so waiting a few more days doesn't hurt and it isn't a pressing subject.

Unless there are other reasons motivating these changes

Well, the dlang/ci PR should have been made ages ago - it's just that nobody thought about it.

[WebDrake]

I don't agree about the CI PR. It's a requirement that dlang/tools is always buildable with latest, greatest master.

Yup, makes sense. I hadn't looked at it properly and misunderstood the intention (I'd assumed it was a PR to make this one possible).

[MartinNowak]

Use dmd-nightly on Travis-CI if you want to test compat of rdmd changes against a recent master dmd, no reason to rebuild binaries.

[WebDrake]

Why were these 3 lines removed? They don't seem related to the rest of the PR and I'd have thought it's convenient to have dmd, rdmd and dub report their versions in the build logs.

[wilzbach]

They are automatically added by our Travis integration.