Use effective date for credit card with deferred payment.

[chemtov]

If the DTUSER is different from the DTPOSTED in an transaction then we
have a deferred payment. Use the effective date in ledger for such
case.

Closes: #69

jseutter/ofxparse#150 needs to be solved before merging this. I've tested this with jseutter/ofxparse#151 and it worked.

[501st-alpha1]

So it has been almost 6 months since jseutter/ofxparse#151 was merged, and there still hasn't been a new release of ofxparse (and in fact there hasn't been since November 2018, almost 2 years ago 😬 ). @egh, would it be possible or desirable to update the version of ofxparse that ledger-autosync uses to the latest from GitHub (or a specific commit) in the meantime?

@chemtov, I'm sure the test failures are because Travis doesn't have the right version of ofxparse, but it looks like there are also some conflicts, so you may want to rebase your branch.

[egh]

So it has been almost 6 months since jseutter/ofxparse#151 was merged, and there still hasn't been a new release of ofxparse (and in fact there hasn't been since November 2018, almost 2 years ago grimacing ). @egh, would it be possible or desirable to update the version of ofxparse that ledger-autosync uses to the latest from GitHub (or a specific commit) in the meantime?

:( It might be possible. I've never done that with a setup.py install. I'll look into it.