Illegal character

Hi and thanks for this nice project!  

Launching this docker-compose on ubuntu gave me an error:
```
ERROR: .UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa9 in position 467: invalid start byte
```
I identified that illegal quote was used here in docker-compose.yml:
```
 PDNS_REMOTE_HTTP_HOST: "ddns:8053"
```

I corrected it and it worked nicely.