Merge pull request AuthorizeNet#54 from AuthorizeNet/future

Future

Update .travis.yml

Update cert.pem

Merge pull request AuthorizeNet#47 from AuthorizeNet/updatedPem

Update cert.pem

Updating the certificate

Update README.md

Merge branch 'ramittal-master'

Anet PHP SDK Release 1.8.1

Initial GH release