Correct atom creation-date element

lib/Parser/XML/Entry.php

@@ -98,7 +98,7 @@ class Entry extends Construct implements \MensBeam\Lax\Parser\Entry {
             formats are equal, and we want the earliest date, but only if 
             there are at least two
         */
-        return $this->fetchDate("atom:created", self::DATE_EARLIEST)            // Atom creation date
+        return $this->fetchDate("atom:published", self::DATE_EARLIEST)          // Atom creation date
             ?? $this->fetchDate("dct:created|dc:created", self::DATE_LATEST)    // Dublin Core creation date
             ?? $this->getAssumedDateCreated();                                  // Earliest other date
     }

tests/cases/XML/entry-atom.yaml

@@ -99,8 +99,8 @@ Creation and update dates:
     input: >
         <feed xmlns="http://www.w3.org/2005/Atom">
             <entry>
-                <created>2020-01-01T00:00:00Z</created>
+                <published>2020-01-01T00:00:00Z</published>
-                <created>2020-03-03T00:00:00Z</created>
+                <published>2020-03-03T00:00:00Z</published>
                 <updated>2020-03-03T00:00:00Z</updated>
                 <updated>2020-04-01T00:00:00Z</updated>
             </entry>

tests/cases/XML/entry-mixed.yaml

@@ -24,7 +24,7 @@ Update and creation dates:
                 <pubDate>2020-03-03T00:00:00Z</pubDate>
             </item>
             <item>
-                <atom:created>2020-03-03T00:00:00Z</atom:created>
+                <atom:published>2020-03-03T00:00:00Z</atom:published>
                 <lastBuildDate>2020-01-01T00:00:00Z</lastBuildDate>
             </item>
             <item>

tests/cases/XML/feed-atom.yaml

@@ -389,7 +389,7 @@ Multiple feed date timezones:
 Bogus feed date:
     input: >
         <feed xmlns="http://www.w3.org/2005/Atom">
-            <created>2020-03-03T00:00:00Z</created>
+            <published>2020-03-03T00:00:00Z</published>
         </feed>
     output:
         format: atom