Merge pull request #13 from andymckay/master

don't allow test-receipt by default
fix backtick
added receipt type links to readme
Merge pull request #14 from nickdesaulniers/readme
small typo in readme
Merge pull request #15 from nickdesaulniers/readme
small correction to readme and typsAllowed
Merge pull request #16 from nickdesaulniers/readme
add in product url checks (bug 867282)