using docker on windows is failing due to errors in the startup scripts configuration

### Summary
- from https://github.com/AgileVentures/av-dashboard/pull/37#pullrequestreview-185359261, the use of docker compose on windows is broken due to issues with the `seed_databash.sh` script.
i.e the error below is shown when the command is ran in Windows docker
```
/usr/bin/env: ‘bash\r’: No such file or directory
```
- this should be fixed before switching to using docker for development on the AV dashboard project

### Acceptance Criteria
- [ ] ensure the script `seed_databash.sh` works on Docker for windows
- [ ] the script should still work on the other supported environment i.e linux and Windows
### Notes
- initial investigation points to an issue with the file ending on the script i.e it used UNIX compatible line ending which are unsupported on windows