Adds feature-100 - attachemtnes from binary/memory

Merge pull request calcinai#99 from coop182/patch-3

URL decode response body before checking 503 error message

Merge pull request calcinai#85 from calcinai/utc-support

UTC support

Merge pull request calcinai#72 from cosmic-beacon/fix-private-example

Fix private example

Update for typo calcinai#36

Merge branch 'master' of https://github.com/calcinai/xero-php

Generated models with use of appropriate traits

Updated models with new gen

Model rebuild for May 4 API release

Updated direct save method to retrospecively populate GUIDs of child …

…objects on save