• logger: use standard lazy formatting (#3487) @efiop
• cmd: diff: don't load dir cache for diff (#3468) @pared
• dvc: support Python3.8 (#3463) @skshetry
• Use pre-commit for Git hooks (#3406) @andrewhare
• list: rename target param to path, update docs (#3462) @JIoJIaJIu
• exceptions: use semantic exceptions (#3430) @skshetry
• checkout: show summary by default and introduce --show-changes flag (#3401) @skshetry
• tests: remove use of mocker as context-manager (#3480) @skshetry
• dvc: optimize all target specific commands to not build graph (#3459) @Suor
• tests: add .gitignore files when upon dvc_add (#3455) @pared
• add: do not verify hardlink if file is empty (#3428) @skshetry
• api: docstring updates (2) (#3426) @jorgeorpinel
• completion: bash: misc fixes and updates (#3467) @casperdcl
• gdrive: support Google Service accounts (#3269) @MaxRis