Dvc

Fixed `gitpython`'s version in dependencies.

* get/import: retrieve files inside directory outs (3309) mroutis
* logger: refactor, remove dead code (3306) mroutis
* update: support specifying revision when updating (3337) skshetry

* schema: use a more flexible hash schema (3333) efiop
* ui: make progress bars respect `--quiet` (3316) casperdcl
* dvc: do not set cache dir if it's not a dvc repo (3329) skshetry
* snap: test: add build and deploy checks (3330) casperdcl
* imp_url: make default stage fname accompany import target (3312) pared
* tests: fix typo on gdrive_client_secret (3327) skshetry
* checkout: change loglevel to debug and simplify message (3326) skshetry
* logger: log datetime when on debug mode (3325) skshetry
* daemon config fix (3324) pared
* erepo: fix known sha handling (3323) Suor
* repo: Prevent repo from setting log level (3321) gauravr
* dvc: refactor config (3298) Suor
* add: meaningful message upon adding overlapping paths (3296) pared
* introduce `dvc list` command (3246) JIoJIaJIu
* black: bump version 19.3b0 -> 19.10b0 (3307) mroutis

* erepo: cache all read only external repos by hexsha (3286) Suor
* GDrive improvements and code cleanup (3294) shcheklein
* repro: fix bug in _get_active_graph (3301) efiop
* diff: use `rev` instead of `ref` (3299) efiop
* repo: raise exception if root_dir is not a directory path (3295) skshetry
* get/import: they don't work with any DVC project, only DVC repos (as well as Git repos) (3277) jorgeorpinel
* add: auto convert absolute_path => relative (2975) casperdcl

* analytics: ignore request.post errors (3292) efiop
* logger: allow exc_info in all record types (3290) efiop

* gdrive: add gc command support (3288) MaxRis
* check root .gitignore in '_ignored' (3284) Aljo-Rovco
* Fix blockers list in rwlock error message (3285) Suor
* rwlock: require info keys to be present in schema (3283) mroutis
* rwlock: include actionable in error message (3270) mroutis