Add s3fd_convert.pth & 2DFAN-4.pth to dockerfile

[HyperDenton]

1. Add --no-cache-dir flag to avoid memory error while building in dockerhub;
2. Add face-alignment model file s3fd_convert.pth and 2DFAN-4.pth, making Avatarify image ready-to-use once pulled or built;
3. This Dockerfile can be built from dockerhub(see https://hub.docker.com/r/denton35/avatarify) and tested on linux GPU machine.

[BugMaker2002]

Hello, I urgently need the s3fd_convert.pth file, could you please give me a copy?