omit old versions when writing versions.json file

Author: kedashoe

bin/write-versions-json

@@ -4,10 +4,15 @@ let FS = require('fs');
 let Process = require('process');
 let semver_cmp = require('semver-compare');
 
+const OLD_VERSIONS = "0.15";
+
 let read_versions_from_fs = () => {
   return (
     FS.readdirSync('.')
       .filter(x => /^(\d+)(\.\d+)*\w*$/.test(x))
+      // We have retained the docs for some old version, but we do not
+      // want to link them as they cannot be generated by the current setup.
+      .filter(x => !OLD_VERSIONS.includes(x))
   );
 };