Update documentation, dependencies, and version sync for 3.2.

Author: gkellogg

.github/workflows/ci.yml

@@ -20,7 +20,6 @@ jobs:
       fail-fast: false
       matrix:
         ruby:
-          - 2.5
           - 2.6
           - 2.7
           - 3.0

README.md

@@ -17,7 +17,7 @@ Install with `gem install rdf-turtle`
 
 * 100% free and unencumbered [public domain](https://unlicense.org/) software.
 * Implements a complete parser for [Turtle][].
-* Compatible with Ruby >= 2.4.
+* Compatible with Ruby >= 2.6.
 * Optional streaming writer, to serialize large graphs
 * Provisional support for [Turtle-star][RDF-star].
 
@@ -140,9 +140,9 @@ This version uses a hand-written parser using the Lexer from the [EBNF][] gem in
 
 ## Dependencies
 
-* [Ruby](https://ruby-lang.org/) (>= 2.4)
-* [RDF.rb](https://rubygems.org/gems/rdf) (~> 3.1)
-* [EBNF][] (~> 1.1)
+* [Ruby](https://ruby-lang.org/) (>= 2.6)
+* [RDF.rb](https://rubygems.org/gems/rdf) (~> 3.2)
+* [EBNF][] (~> 1.2)
 
 ## Installation
 

VERSION

@@ -1 +1 @@
-3.1.3
+3.2.0

rdf-turtle.gemspec

@@ -18,17 +18,17 @@ Gem::Specification.new do |gem|
   gem.files                 = %w(AUTHORS README.md History UNLICENSE VERSION) + Dir.glob('lib/**/*.rb')
   gem.require_paths         = %w(lib)
 
-  gem.required_ruby_version = '>= 2.4'
+  gem.required_ruby_version = '>= 2.6'
   gem.requirements          = []
-  gem.add_runtime_dependency     'rdf',             '~> 3.1', '>= 3.1.8'
-  gem.add_runtime_dependency     'ebnf',            '~> 2.1'
+  gem.add_runtime_dependency     'rdf',             '~> 3.2'
+  gem.add_runtime_dependency     'ebnf',            '~> 2.2'
   gem.add_development_dependency 'erubis',          '~> 2.7'
   gem.add_development_dependency 'htmlentities',    '~> 4.3'
   gem.add_development_dependency 'rspec',           '~> 3.10'
   gem.add_development_dependency 'rspec-its',       '~> 1.3'
-  gem.add_development_dependency 'rdf-isomorphic',  '~> 3.1'
-  gem.add_development_dependency 'json-ld',         '~> 3.1'
-  gem.add_development_dependency 'rdf-spec',        '~> 3.1'
-  gem.add_development_dependency 'rdf-vocab',       '~> 3.1'
+  gem.add_development_dependency 'rdf-isomorphic',  '~> 3.2'
+  gem.add_development_dependency 'json-ld',         '~> 3.2'
+  gem.add_development_dependency 'rdf-spec',        '~> 3.2'
+  gem.add_development_dependency 'rdf-vocab',       '~> 3.2'
   gem.post_install_message  = nil
 end