Support for repositories with git LFS

[pavelpokutnev]

The current "[email protected]" fails with following error in case it is applied to repository with git LFS enabled:

  Checking out the gh-pages branch (keeping its history) from commit ...
  git-lfs filter-process: line 0: git-lfs: not found
  fatal: the remote end hung up unexpectedly

The issue is that the base alpine docker image doesn't installs the git-lfs, so it is not available.

Proposals:

• Option 1: add something like following into the Dockerfile

  RUN apk add --no-cache \
          git-lfs

• Option 2: add the git-lfs install into the entrypoint.sh

  # Install git-lfs since it is not in alpine base image.
  echo "Install git LFS"
  apk update
  apk add --update git-lfs