Update json-schema dependency

Version 2.8.0 of the json-schema gem assumed the WIP draft 6 URI would
be "http://json-schema.org/draft-06/schema#".  It happens that it is in
fact "http://json-schema.org/draft/schema#".

This was fixed in:
voxpupuli/json-schema#376

json-schema PATCH vesion was bumped, so that version 2.8.1 include this
fix.

Instead of depending on a buggy version of this gem and using the same
wrong URI, switch to the fixed version of the gem and use the expected
URI.

lib/pdk/config/analytics_schema.json

@@ -1,6 +1,6 @@
 {
   "definitions": {},
-  "$schema": "http://json-schema.org/draft-06/schema#",
+  "$schema": "http://json-schema.org/draft/schema#",
   "$id": "http://puppet.com/schema/does_not_exist.json",
   "type": "object",
   "title": "The PDK Analytics YAML Schema",

lib/pdk/config/json_schema_namespace.rb

@@ -105,7 +105,7 @@ def create_missing_setting(key, _initial_value = nil)
       # @return [JSON::Schema]
       def create_empty_schema
         require 'json-schema'
-        ::JSON::Schema.new({}, 'http://json-schema.org/draft-06/schema#')
+        ::JSON::Schema.new({}, 'http://json-schema.org/draft/schema#')
       end
 
       # Lazily retrieve the JSON schema from disk for this namespace

pdk.gemspec

@@ -26,7 +26,7 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'ffi', '~> 1.9.0'
   spec.add_runtime_dependency 'gettext-setup', '~> 0.24'
   spec.add_runtime_dependency 'hitimes', '1.3.0'
-  spec.add_runtime_dependency 'json-schema', '2.8.0'
+  spec.add_runtime_dependency 'json-schema', '~> 2.8.1'
   spec.add_runtime_dependency 'json_pure', '~> 2.1.0'
   spec.add_runtime_dependency 'minitar', '~> 0.6.1'
   spec.add_runtime_dependency 'pathspec', '~> 0.2.1'

spec/support/file_based_namespaces.rb

@@ -86,7 +86,7 @@
         <<-SCHEMA
         {
           "definitions": {},
-          "$schema": "http://json-schema.org/draft-06/schema#",
+          "$schema": "http://json-schema.org/draft/schema#",
           "$id": "http://puppet.com/schema/does_not_exist.json",
           "type": "object",
           "title": "A Schema",

spec/unit/pdk/config/json_schema_namespace_spec.rb

@@ -23,7 +23,7 @@ def load_and_ignore(namespace)
       <<-SCHEMA
       {
         "definitions": {},
-        "$schema": "http://json-schema.org/draft-06/schema#",
+        "$schema": "http://json-schema.org/draft/schema#",
         "$id": "http://puppet.com/schema/does_not_exist.json",
         "type": "object",
         "title": "A Schema",
@@ -74,7 +74,7 @@ def load_and_ignore(namespace)
             <<-SCHEMA
             {
               "definitions": {},
-              "$schema": "http://json-schema.org/draft-06/schema#",
+              "$schema": "http://json-schema.org/draft/schema#",
               "$id": "http://puppet.com/schema/does_not_exist.json",
               "type": "object",
               "title": "A Schema",
@@ -104,7 +104,7 @@ def load_and_ignore(namespace)
       <<-SCHEMA
       {
         "definitions": {},
-        "$schema": "http://json-schema.org/draft-06/schema#",
+        "$schema": "http://json-schema.org/draft/schema#",
         "$id": "http://puppet.com/schema/does_not_exist.json",
         "type": "object",
         "title": "A propertyless Schema"

spec/unit/pdk/config/json_schema_setting_spec.rb

@@ -28,7 +28,7 @@
       <<-SCHEMA
       {
         "definitions": {},
-        "$schema": "http://json-schema.org/draft-06/schema#",
+        "$schema": "http://json-schema.org/draft/schema#",
         "$id": "http://puppet.com/schema/does_not_exist.json",
         "type": "object",
         "title": "A Schema",
@@ -66,7 +66,7 @@
       <<-SCHEMA
       {
         "definitions": {},
-        "$schema": "http://json-schema.org/draft-06/schema#",
+        "$schema": "http://json-schema.org/draft/schema#",
         "$id": "http://puppet.com/schema/does_not_exist.json",
         "type": "object",
         "title": "A Schema",

spec/unit/pdk/config/json_with_schema_spec.rb

@@ -23,7 +23,7 @@
     <<-SCHEMA
     {
       "definitions": {},
-      "$schema": "http://json-schema.org/draft-06/schema#",
+      "$schema": "http://json-schema.org/draft/schema#",
       "$id": "http://puppet.com/schema/does_not_exist.json",
       "type": "object",
       "title": "A Schema",

spec/unit/pdk/config/schema_files_spec.rb

@@ -9,7 +9,7 @@
 
       it 'is a valid JSON schema document' do
         # The Schema Document specifies which schema version it uses
-        expect(schema['$schema']).to match(%r{draft-[\d]+})
+        expect(schema['$schema']).to match(%r{draft/schema#\z})
         metaschema = JSON::Validator.validator_for_name(schema['$schema']).metaschema
 
         expect(JSON::Validator.validate(metaschema, schema)).to be true

spec/unit/pdk/config/yaml_with_schema_spec.rb

@@ -23,7 +23,7 @@
     <<-SCHEMA
     {
       "definitions": {},
-      "$schema": "http://json-schema.org/draft-06/schema#",
+      "$schema": "http://json-schema.org/draft/schema#",
       "$id": "http://puppet.com/schema/does_not_exist.json",
       "type": "object",
       "title": "A Schema",