Update dependenies.

Author: gkellogg

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 2.7
+        ruby-version: 3.1
     - name: Install dependencies
       run: bundle install
 

Gemfile

@@ -1,12 +1,8 @@
 source "https://rubygems.org"
 
-gem 'json-ld', github: 'ruby-rdf/json-ld', branch: 'develop'
-gem 'rdf-isomorphic', github: 'ruby-rdf/rdf-isomorphic', branch: 'develop'
 gem 'linkeddata'
-gem 'rdf-trig', github: 'ruby-rdf/rdf-trig', branch: 'develop'
 gem 'earl-report'
 gem 'nokogiri'
-gem 'nokogumbo'
 gem 'colorize'
 gem 'rake'
 gem 'redcarpet'