Justpath

- [x] Added `--shell-equivalents` flag (https://github.com/epogrebnyak/justpath/issues/15)
- [x] Added `--follow-symlinks` flag (https://github.com/epogrebnyak/justpath/issues/11)

1. Changed CLI to be one command with flags:


justpath --raw
justpath
justpath --count
justpath --invalid
justpath --duplicates
justpath --correct --string


2. Added `--purge-duplicates` that removes duplicate directories from `PATH`

3. Modified `--count` output.

4. Small writeup at <https://polar.sh/epogrebnyak/posts/justpath-to-explore-path-quickly> and [hackernews](https://news.ycombinator.com/item?id=39493363)

- Allows inspection and cleaning of `PATH` variable,
- Three commands: `raw`, `show` and `count`
- Feedback from [a reddit post](https://www.reddit.com/r/Python/comments/1ac7fao/pathit_just_show_me_my_path_in_way_i_can_read_it/)
- Testing with `CliRunner` and `subprocess.call`
- `pip install justpath`
- Two stars on Github and two issues submitted by users