Add support for multiple positional path arguments

[guykisel]

This is an attempt at resolving #61

Example usage: prospector tests/test_autodetect.py setup.py prospector/tools

[guykisel]

My basic manual attempts at testing this have worked, but I suspect there are a lot of edge cases that would break this.

[guykisel]

I think one of the major issues to figure out in this sort of solution is how best to communicate what tools/profiles were run on what files/folders, since right now there's just one unified summary. Individual summaries per file could end up looking pretty cluttered.

[carlio]

@guykisel Thanks for the pull request, sorry I didn't get around to looking at it earlier.

I think you hit the nail on the head with your last comment - with this approach, it's very hard to communicate what settings were used in which folder. By having a separate Prospector instance per input folder, it's equivalent to a bash command like this:

for p in path1 path2 path3
do
    prospector $p
done

The bash command has the benefit of being more explicit for where it finds config too!

There are several options:

1. only allow multi-path for files rather than folders, which removes the ambiguity, or
2. implicitly use only the first directory listed for config, or
3. simply document why multi-path isn't a good plan for prospector.

Personally I think 1) is the best approach but it's a bit tricky to communicate in documentation and the --help output...

[guykisel]

@carlio thanks for the comments. I agree that 1) sounds best. I'm thinking that in addition to documentation and notes in --help, Prospector could raise a warning or error if a directory path is passed in along with other paths.

I'll continue experimenting with this.

[guykisel]

@carlio also, I saw your update to contrib.rst about opening PRs against develop. If you like, I can close this and reopen it as a PR to develop, or I can just wait until I have something more mature before opening a new PR.

[carlio]

@guykisel No worries, the PR against master is fine, it's not a big deal at all!