Vcspull

- [api] Change the API of :class:`vcspull.repo.base.BaseRepo` and
:class:`vcspull.repo.Repo` to accept arguments as `kwargs`
- [api]: Rename `parent_path` to `cwd`.
- [docs]: Pydoc documentation for `Repo` usage.
- [docs]: Python API example

- [testing] Fix sniffer on Python 3
- [cli] remove redundant message when adding remotes
- [docs] add animated screencast preview for ReadTheDocs and README.rst

- [cli]: support for specifying for config file path with `-c`.
- [cli]: clarify error output when no repositories found

- [internals]: move to `__about__.py` convention for pulling package
data.
- [internals]: remove extraneous url from stdout in git repositories.

- [cli] Update documentation when no config found to show `yaml` and
`json`. Remove mentioning of `conf`.

- [logging] [6] - fix issue where log templates would not
concatenate correctly.

[6]: https://github.com/vcs-python/vcspull/issues/6