1) [Added additional unit tests for fs utils](https://github.com/iterative/dvc/pull/2673);
2) [Temporarily hidden `--all-commits` flag for `gc`](https://github.com/iterative/dvc/pull/2682);
3) [Refactored backtics and single-quotes usage in the code](https://github.com/iterative/dvc/pull/2644);
4) [Added a workaround for flufl.lock bug](https://github.com/iterative/dvc/pull/2688);
5) [Fixed bug when pulling imported directories](https://github.com/iterative/dvc/pull/2692);