`tag_create` missing

[tammoippen]

The function tag_create is used but not defined.

[cameronsstone]

Here's a go at it.
Notes:

1. I've change the "type" named arg into a boolean.
2. I'm not even close to confident in the bstring parts.
3. I was guessing a lot about the tag object format.

def tag_create(repo: GitRepository, name, reference, create_tag_object):
    # get the GitObject from the object reference
    sha = object_find(repo, reference)

    if create_tag_object:
        # create tag object (commit)
        tag = GitTag(repo)
        tag.kvlm = collections.OrderedDict()
        tag.kvlm[b'object'] = sha.encode()
        tag.kvlm[b'type'] = b'commit'
        tag.kvlm[b'tag'] = name.encode()
        tag.kvlm[b'tagger'] = b'The soul eater <grim@reaper.net>'
        tag.kvlm[b''] = b'This is the commit message that should have come from the user\n'
        tag_sha = object_write(tag, repo)
        # create reference
        ref_create(repo, "tags/" + name, tag_sha)
    else:
        # create lightweight tag (ref)
        ref_create(repo, "tags/" + name, sha)

def ref_create(repo, ref_name, sha):
    with open(repo_file(repo, "refs/" + ref_name), 'w') as fp:
        fp.write(sha + "\n")

Feel free to convert this into a pull request.

[thblt]

Thanks!

[cameronsstone]

Hooray!