Set up flit for briar-wrapper

Closes
#2.
3 jobs for 2-configure-flit in 2 minutes and 8 seconds (queued for 1 minute)
Status Job ID Name Coverage
  Test
passed #4456
pycodestyle

00:00:39

passed #4457
pylint

00:00:46

passed #4458
pytest

00:00:42

47.0%