Finish 1.1.3.1. Implement callback modes for #each_statement and #each_triple.
Update Travis Ruby versions.
Clean up options passed to Kernel.open/OpenURI.
This addresses issue #10.
Add support for :unique_bnodes to writer.
Version 1.1.4.
Finish 1.1.4.

* Add support for :unique_bnodes to writer.