test: Remove file_get_contents override and incorrect/invaluable tests

Overriding file_get_contents introduces different behaviour from the native function, such as the $http_response_headers missing. Removing the override revealed two test (testing a specific return path of the file_get_contents method rather then testing the behaviour or result of the subject under test) which had different behaviour between the test and runtime, therefor these tests have been removed.

Author: DannyvdSluijs

tests/Uri/Retrievers/FileGetContentsTest.php

@@ -26,28 +26,6 @@ public function testFetchFile()
             $this->assertNotEmpty($result);
         }
 
-        public function testFalseReturn()
-        {
-            $res = new FileGetContents();
-
-            $this->setExpectedException(
-                '\JsonSchema\Exception\ResourceNotFoundException',
-                'JSON schema not found at http://example.com/false'
-            );
-            $res->retrieve('http://example.com/false');
-        }
-
-        public function testFetchDirectory()
-        {
-            $res = new FileGetContents();
-
-            $this->setExpectedException(
-                '\JsonSchema\Exception\ResourceNotFoundException',
-                'JSON schema not found at file:///this/is/a/directory/'
-            );
-            $res->retrieve('file:///this/is/a/directory/');
-        }
-
         public function testContentType()
         {
             $res = new FileGetContents();
@@ -70,15 +48,3 @@ public function testCanHandleHttp301PermanentRedirect()
         }
     }
 }
-
-namespace JsonSchema\Uri\Retrievers
-{
-    function file_get_contents($uri)
-    {
-        switch ($uri) {
-            case 'http://example.com/false': return false;
-            case 'file:///this/is/a/directory/': return '';
-            default: return \file_get_contents($uri);
-        }
-    }
-}