Bump known working nightly version
Bump known working nightly version

There were upstream changes in rustc, which have been resolved in aster,
quasi, etc, but the versions that will resolve as it is no longer build
on 2015-12-30

sgrif/diesel,mcasper/diesel,sgrif/diesel,cascalheira/diesel,SoftwareWarlock/diesel,diesel-rs/diesel,cascalheira/diesel,diesel-rs/diesel,tohou/diesel,SoftwareWarlock/diesel,tohou/diesel,mcasper/diesel