Release 1.1.5.2.

* Don't use special version of RDF::UTIL::File.open_file, but make sure User-Agent header is set properly
Update for linkeddata 1.1.2.
Ruby 2.1.5 in travis
Use RestClient to cache some requests.
Add verify_none option to be more forgiving about SSL issues.
Version 1.1.6.
Release 1.1.6

* Update for linkeddata 1.1.2.
* Use RestClient to cache some requests.
* Add verify_none option to be more forgiving about SSL issues.