Explicitly define sep program and needle exchange service with slug in seed

[MikeyManoguerra]

since the service slug becomes a hardcoded value, we should not rely on programmatic creation of the slug in the loop, but instead create them explicitly in seed.py

slug is 'sep-needle-exchange' (see constants directory in front end)

Probably just remove that program from the loop entirely and create it as a one-off after the other programs are created