Add ignoring password entires in auditing

[ltecheroffical]

Because of the fact that password-store stores passwords (secrets) in a encrypted text file, it's not good that a note written there would be flagged quickly and annoy you. So it's a safe bet to add an option to ignore passwords, so this Pull Request adds .pass-audit-ignore as a file that can be created in the password store directory to ignore passwords with the prefix. For example, ignoring passwords in a dir is easy. For example, here is one that ignores passwords in a directory called test:

Test/

[roddhjav]

Hi, thanks for your PR.

That is a nice feature, can you add the corresponding unit tests?

Because of the fact that password-store stores passwords (secrets) in plaintext

Hum, what?

[ltecheroffical]

plaintext = encrypted text files (typo)

Also, without knowledge of how you run tests, I can't write them.