seed script with hard-coded variables

[mariekers]

Separate the hard-coded (currently true) django objects from faked data script

The harded coded objects should be populated with real, PPP data.

These objects are:

• sep sites
• programs
• services
• program_availability

[MikeyManoguerra]

@alex-cots this seed should explicitly define the slug that is used in the front end in the sep service.

prevention-point/frontend/src/constants/index.js

Line 54 in ec290b9

export const SYRINGE_EXCHANGE_SLUG = "sep-needle-exchange"

that is what my branch generates programmatically, but i want to be sure its the same and hardcode it