Support exclude-old-transactions Request parameter

[brandon-clair]

This adds support for sending the exclude-old-transactions Request parameter to App Store receipt validation.

Apple Docs
https://developer.apple.com/library/content/releasenotes/General/ValidateAppStoreReceipt/Chapters/ValidateRemotely.html

[coveralls]

Coverage increased (+0.03%) to 88.657% when pulling b5e2fb7 on brandon-clair:master into 16ade8e on youknowone:master.

[codecov]

Codecov Report

Merging #39 into master will increase coverage by 0.03%.
The diff coverage is 75%.

@@            Coverage Diff             @@
##           master      #39      +/-   ##
==========================================
+ Coverage   88.62%   88.66%   +0.03%     
==========================================
  Files           8        8              
  Lines         334      335       +1     
==========================================
+ Hits          296      297       +1     
  Misses         38       38

[youknowone]

Thanks for the new feature support. Can you add test for it? The test needs to cover both of True and False cases.

To make the change clear: the response format was not changed, right?

[brandon-clair]

@youknowone A test has been added! Since the parameter is optional, and defaults to False, the current suite of tests cover that case. I have added a case where the parameter is submitted as True.

Correct, the response format has not been altered. This is to support a new, optional parameter for verification requests, exclude-old-transactions.

[coveralls]

Coverage increased (+0.03%) to 88.657% when pulling 7c7e174 on brandon-clair:master into 16ade8e on youknowone:master.

[coveralls]

Coverage increased (+0.03%) to 88.657% when pulling 7c7e174 on brandon-clair:master into 16ade8e on youknowone:master.

[coveralls]

Coverage increased (+0.03%) to 88.657% when pulling 7c7e174 on brandon-clair:master into 16ade8e on youknowone:master.

[coveralls]

Coverage increased (+0.03%) to 88.657% when pulling 7c7e174 on brandon-clair:master into 16ade8e on youknowone:master.

[youknowone]

I merged it, thanks!