added DatatypeEnum tests; repaired the other test for local execution; small bug fixes

src/enums/DatatypeEnum.php

@@ -66,9 +66,9 @@ class DatatypeEnum
                     return $type;
                 }
             }
-
-            return self::__DEFAULT;
         }
+
+        return self::__DEFAULT;
     }
 
     /**

src/extensions/DatatypeTrait.php

@@ -23,7 +23,11 @@ trait DatatypeTrait {
      * @return string|false
      */
     private function getMostFrequentDataypeForColumn($datatypes) {
-        array_filter($datatypes);     
+        array_filter($datatypes);
+
+        if (empty($datatypes)){
+            return false;
+        }
 
         // workaround because array_count_values($datatypes) does not work anymore :-(
         foreach ($datatypes as $type) {