Force 32-bit compilation on Travis
Fixes calls to LAPACK.stebz

Fixes crash in eigenvalue computations for SymTridiagonal matrices
Merge pull request #2609 from jiahao/issue-2606

Fixes calls to LAPACK.stebz
Merge branch 'master' of https://github.com/JuliaLang/julia into travistest
Merge pull request #2605 from staticfloat/travistest

Force 32-bit compilation on travis