[FEATURE REQUEST] Option to respect .gitignore

[NoamNol]

Add option to ignore all files in .gitignore.

In ESLint it's possible with:

eslint --ignore-path .gitignore

Related to #445 (but now I don't ask to change the default behavior)

[carlio]

Out of curiosity, which python files to you keep locally which are not checked in which prospector would otherwise pick up? Has this been a problem so far?

Virtual environments and tox config should already be automatically ignored.

I agree that this feature makes sense, I just want to understand the use case better to help me understanding when implementing it.

[NoamNol]

In my case I have a folder for private code ignored by git.

[carlio]

Ok I see.

I will park this for now, because I have a plan to rewrite how prospector finds files to inspect as it is. I have to clean out the backlog of bugs first, but once that is done I'll move onto the file-finder-rewrite (see the label) and include this.

[NoamNol]

Great! and I think in the future prospector can move to ignorefiles (one or many) and completely remove the ignore-paths and ignore-patterns options.

But this is beyond the scope of this issue.