Merge pull request sendinblue#6 from sendinblue/feature_mixed-updates

Delete single contact method added + get account response fix for reseller

Merge pull request sendinblue#5 from sendinblue/feature_mixed-spec-up…

…dates

Mixed specification updates

Merge pull request sendinblue#4 from sendinblue/hotfix-byteattachment

Fix sending with attachment API through Json Serializer

Initial release of SendinBlue API V3 Java Package

Initial release of SendinBlue API V3 Java Package