Use 'fields' order if resource's fields are explicitly defined in the meta class.
This allows users not avoid redefining another 'export_order' list just to change the ordering.
Add basic example of dehydration to docs.
Add .travis.yml for running automated tests.
Add .travis.yml for running automated tests.
Add build status to README
Merge branch 'dehydrate_docs'
Merge branch 'export_order_patch'