Adding mapping for Amazon purchases.

[jaraco]

No description provided.

[jaraco]

I've added tests, but due to #102 and #103 and #104, I'm giving up on trying to run the tests. Please refine the tests to your tastes, and let me know if there's more I can do to refine the implementation.

[jaraco]

After submitting this PR, I'm now beginning to wonder if I should use a different model for inclusion/exclusion of payment methods. Originally, I had a simpler use-case, but now I'm discovering that exclusion is too lenient and picks up unwanted transactions. I'm now reconsidering whether "inclusion" should be customizable too.

[reubano]

After submitting this PR, I'm now beginning to wonder if I should use a different model for inclusion/exclusion of payment methods. Originally, I had a simpler use-case, but now I'm discovering that exclusion is too lenient and picks up unwanted transactions. I'm now reconsidering whether "inclusion" should be customizable too.

Ok, let me know what you decide. Unless you are saying the lib is missing a needed feature.

[jaraco]

After submitting this PR, I'm now beginning to wonder if I should use a different model for inclusion/exclusion of payment methods. Originally, I had a simpler use-case, but now I'm discovering that exclusion is too lenient and picks up unwanted transactions. I'm now reconsidering whether "inclusion" should be customizable too.

Ok, let me know what you decide. Unless you are saying the lib is missing a needed feature.

Sorry. I could have followed up. In 4cd5884, I added both inclusion and exclusion support, so it's ready to be reviewed in its current state.