Ignore alpha builds

Author: sivakumar-kailasam

lib/fetch-yui-docs.js

@@ -7,7 +7,11 @@ import pkgVersions from 'pkg-versions'
 import { all, resolve } from 'rsvp'
 
 let filterValidVersions = (specificDocsVersion, ignorePreviouslyIndexedDoc) => version => {
-	let isCompatibleVersion = compareVersions(version, '3.4.1') !== -1 && !version.includes('beta') && !version.includes('canary')
+	let isCompatibleVersion =
+		compareVersions(version, '3.4.1') !== -1 &&
+		!version.includes('beta') &&
+		!version.includes('canary') &&
+		!version.includes('alpha')
 
 	if (!isEmpty(trim(specificDocsVersion)) && !ignorePreviouslyIndexedDoc) {
 		return isCompatibleVersion && version.includes(specificDocsVersion)