devserver: Basic healthchecks for devserver.

This CL provides some basic healthchecks for the
devserver for use with the Mob* Monitor. It
provides checks for:
 - ensuring a Boto key is present
 - ensuring we can access google storage

TEST=Deployed and tested on a moblab.

Change-Id: I4543e1d47541d82cbaf0318382d89fa01f6a976c
Commit-Ready: Matthew Sartori <>
Tested-by: Matthew Sartori <>
Reviewed-by: Matthew Sartori <>
2 files changed