1. Implement `--time` to `exp gc`
2. add a unit test for it.
3. Rename `--time` to `--date` and change the warning msg.
4. To get a better msg for `gc` and `exp gc`
Co-authored-by: Peter Rowlands (변기호) <[email protected]>
Co-authored-by: Dave Berenbaum <[email protected]>
fix#678
1. Add a new flag `--time` to `dvc gc`.
2. Modify the unit test of `dvc gc`
3. Fix an argument checking error and update the error msg.
Co-authored-by: Dave Berenbaum <[email protected]>
David de la Iglesia Castro
