Remove implementation references to draft 5

Author: adamvoss

_data/validator-cli.yaml

@@ -3,13 +3,11 @@
   url: 'https://www.npmjs.com/package/ajv-cli'
   draft:
     - 4
-    - 5
     - 6
 - name: Polyglottal JSON Schema Validator
   license: MIT
   url: 'https://www.npmjs.com/package/pajv'
   draft:
     - 4
-    - 5
     - 6
   notes: can be used with YAML and many other formats besides JSON

_data/validator-libraries.yml

@@ -99,7 +99,7 @@
     - name: ajv
       url: https://github.com/epoberezkin/ajv
       notes: "for Node.js and browsers - *supports [custom keywords](https://github.com/epoberezkin/ajv-keywords) and [$data reference](https://github.com/json-schema-org/json-schema-spec/issues/51)*"
-      draft: [4, 5, 6]
+      draft: [4, 6]
       license: MIT
     - name: djv
       url: https://github.com/korzio/djv