Add savannah-raspbian worker

[savannahostrowski]

Closes #632

[itamaro]

1. avoid duplicate builder name
2. consider initially adding this builder to the unstable builders list, and moving it to stable only after it proved stable for a few days / weeks

[vstinner]

Aha, a debug build on Raspberry Pi is going to be interesting :-)

[vstinner]

The builder was added and has two jobs in its queue but it seems like it didn't pick the first job yet: https://buildbot.python.org/#/builders/1829

cc @savannahostrowski @encukou

[StanFromIreland]

We actually had a debug pi for a few weeks, the build time was quite long.

[encukou]

From here it looks like the builder looks offline.
@savannahostrowski, is it on? :)

[vstinner]

And the first build is a success! The second build as well: maximum system load of 11.19 (for 4 CPUs) and Total duration: 15 min 29 sec which is quite good!

[StanFromIreland]

Something odd happened in this run during the results upload, otherwise all green.

[savannahostrowski]

I'm unfamiliar, is there a way to run that one again? I modified some configuration on my end and want to see if it gets resolved.

[StanFromIreland]

There is a "Rebuild" button in the corner, I can run it for you:

[savannahostrowski]

Ah got it - thanks, I missed that 🤦‍♀️