Make more consistent use of async/await (#2219)

In #2028 I suggested that we update as much of the code as possible to make consistent use of async await. This snags a bunch of the utility code and attempts to do that.

lib/php-version.js

@@ -5,6 +5,7 @@
  */
 'use strict'
 
+const { promisify } = require('util')
 const request = require('request')
 const uniq = require('lodash.uniq')
 const { listCompare } = require('./version')
@@ -216,26 +217,23 @@ function versionReduction(versions, phpReleases) {
   return versions.join(', ')
 }
 
-function getPhpReleases(githubApiProvider, cb) {
-  regularUpdate(
-    {
-      url: '/repos/php/php-src/git/refs/tags',
-      intervalMillis: 24 * 3600 * 1000, // 1 day
-      scraper: tags =>
-        uniq(
-          tags
-            // only releases
-            .filter(
-              tag => tag.ref.match(/^refs\/tags\/php-\d+\.\d+\.\d+$/) != null
-            )
-            // get minor version of release
-            .map(tag => tag.ref.match(/^refs\/tags\/php-(\d+\.\d+)\.\d+$/)[1])
-        ),
-      request: (url, options, cb) =>
-        githubApiProvider.request(request, url, {}, cb),
-    },
-    cb
-  )
+function getPhpReleases(githubApiProvider) {
+  return promisify(regularUpdate)({
+    url: '/repos/php/php-src/git/refs/tags',
+    intervalMillis: 24 * 3600 * 1000, // 1 day
+    scraper: tags =>
+      uniq(
+        tags
+          // only releases
+          .filter(
+            tag => tag.ref.match(/^refs\/tags\/php-\d+\.\d+\.\d+$/) != null
+          )
+          // get minor version of release
+          .map(tag => tag.ref.match(/^refs\/tags\/php-(\d+\.\d+)\.\d+$/)[1])
+      ),
+    request: (url, options, cb) =>
+      githubApiProvider.request(request, url, {}, cb),
+  })
 }
 
 module.exports = {