Added LFS config, removed modules

This is the start of migration the asset storage to LFS. This will close #71 (closed).

With the new system, any files that are of types that aren't text based will be uploaded to Git LFS, as can be seen here,

Check out that page here if you like.

From the developer or artist's side, they just commit and push the LFS files as if they were text files. This is what the push looks like.

$ git push
Locking support detected on remote "origin". Consider enabling it with:
  $ git config lfs.https://gitlab.com/veloren/veloren.git/info/lfs.locksverify true
Uploading LFS objects: 100% (243/243), 11 MB | 325 KB/s, done                                                                                                                                         
Counting objects: 265, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (264/264), done.
Writing objects: 100% (265/265), 42.08 KiB | 2.80 MiB/s, done.
Total 265 (delta 2), reused 2 (delta 0)
remote: Resolving deltas: 100% (2/2), completed with 1 local object.
remote: 
remote: View merge request for add-lfs-asset-storage-system:
remote:   https://gitlab.com/veloren/veloren/merge_requests/103
remote: 
To gitlab.com:veloren/veloren.git
   5b5bc7a..84c0881  add-lfs-asset-storage-system -> add-lfs-asset-storage-system