add .py suffix to the Python scripts

diff --git a/ftabs b/ftabs.py
similarity index 100%
rename from ftabs
rename to ftabs.py

diff --git a/poudriere-runner b/poudriere-runner.py
similarity index 100%
rename from poudriere-runner
rename to poudriere-runner.py

diff --git a/sss b/sss.py
similarity index 100%
rename from sss
rename to sss.py

diff --git a/up b/up.py
similarity index 100%
rename from up
rename to up.py