rework python scripts to support Python 2 & 3

We run the unittests in both python versions to maintain coverage,
and we run things through `cros lint` during upload to help prevent

We also switch the default to Python 3 to keep people on their toes.

TEST=running unittests against python2 & python3 pass
TEST=`./ bin/example.bin` through python2 & python3 works

Change-Id: I79f0ce59664ea42dfa18e45ccde0dffc0c18227d
Tested-by: Mike Frysinger <>
Commit-Ready: Mike Frysinger <>
Legacy-Commit-Queue: Commit Bot <>
Reviewed-by: Duncan Laurie <>
3 files changed