dashboard: add linux-arm and linux-arm-arm5 builders
dashboard: add linux-arm and linux-arm-arm5 builders

Change-Id: Ib8997f76bdf7965d34543cbb6221d6bdb25246fa
Reviewed-on: https://go-review.googlesource.com/9840
Reviewed-by: David Crawshaw <a2f0bf29257797dd66800b4fbb9945c3e216c004@golang.org>

evandbrown/build,evandbrown/build,golang/build,proppy/build,golang/build,evandbrown/build,proppy/build,golang/build,proppy/build,proppy/build,golang/build