Version 1.1.6.
Release 1.1.6.

* Add :simple_compact_iri option to only use simple terms when creating compact IRIs.
* Enable SSL mode, and don't verify, when retrieving files.
* Added Context#from_vocabulary and script/gen_context to generate a JSON-LD context given an RDFS/OWL/schema.org vocabulary.
* Make loading remote context error fail, even if validate is not set (#11).
* Added :frame option to writer to specify frame to be used instead of context.
* Added Context#reverse_term to find a term definition reversed from that requested.
* Make Context#mappings, #mapping, and #languages private (used only in tests).
* Make Context#alias and #coerce protected.
* Added Context#find_definition to find a term definition.
* Detect lists having nodes shared across different graphs, and add fromRdf test to check for this.