Update gemfile depdendencies.

Author: gkellogg

Gemfile

@@ -15,7 +15,7 @@ group :development do
   gem 'rdf-turtle',         github: "ruby-rdf/rdf-turtle",          branch: "develop"
   gem 'rdf-vocab',          github: "ruby-rdf/rdf-vocab",           branch: "develop"
   gem "rdf-xsd",            github: "ruby-rdf/rdf-xsd",             branch: "develop"
-  gem 'sxp',                github: "gkellogg/sxp-ruby"
+  gem 'sxp',                github: "gkellogg/sxp-ruby",            branch: "develop"
 
   gem "equivalent-xml"
 end

Gemfile-pure

@@ -15,7 +15,7 @@ group :development do
   gem 'rdf-turtle',         github: "ruby-rdf/rdf-turtle",          branch: "develop"
   gem 'rdf-vocab',          github: "ruby-rdf/rdf-vocab",           branch: "develop"
   gem "rdf-xsd",            github: "ruby-rdf/rdf-xsd",             branch: "develop"
-  gem 'sxp',                github: "gkellogg/sxp-ruby"
+  gem 'sxp',                github: "gkellogg/sxp-ruby",            branch: "develop"
 
   gem "equivalent-xml"
 end