replace invalid filesystem dependent DIRECTORY_SEPARATOR references in uri mechanics by forward slashes

- fixes failing UriResolver tests on windows systems

Author: alexmmm

src/JsonSchema/Uri/UriResolver.php

@@ -126,7 +126,7 @@ public static function combineRelativePathWithBasePath($relativePath, $basePath)
         $basePathSegments = array_slice($basePathSegments, 0, -$numLevelUp);
         $path = preg_replace('|^/?(\.\./(\./)*)*|', '', $relativePath);
 
-        return implode(DIRECTORY_SEPARATOR, $basePathSegments) . '/' . $path;
+        return implode('/', $basePathSegments) . '/' . $path;
     }
 
     /**
@@ -148,7 +148,7 @@ private static function normalizePath($path)
      */
     private static function getPathSegments($path) {
 
-        return explode(DIRECTORY_SEPARATOR, $path);
+        return explode('/', $path);
     }
 
     /**

src/JsonSchema/Uri/UriRetriever.php

@@ -282,7 +282,7 @@ private static function combineRelativePathWithBasePath($relativePath, $basePath
         $basePathSegments = array_slice($basePathSegments, 0, -$numLevelUp);
         $path = preg_replace('|^/?(\.\./(\./)*)*|', '', $relativePath);
 
-        return implode(DIRECTORY_SEPARATOR, $basePathSegments) . '/' . $path;
+        return implode('/', $basePathSegments) . '/' . $path;
     }
 
     /**
@@ -304,7 +304,7 @@ private static function normalizePath($path)
      */
     private static function getPathSegments($path)
     {
-        return explode(DIRECTORY_SEPARATOR, $path);
+        return explode('/', $path);
     }
 
     /**