prevent to send unexpected requests in tests

Author: oscarotero

.gitattributes

@@ -1,6 +1,7 @@
 /demo             export-ignore
 /tests            export-ignore
 /scripts          export-ignore
+/.github          export-ignore
 .gitattributes    export-ignore
 .gitignore        export-ignore
 .php_cs.dist      export-ignore

tests/PagesTest.php

@@ -6,11 +6,12 @@
 class PagesTest extends PagesTestCase
 {
     /**
+     * -1 = Read from cache (throws an exception if the cache doesn't exist)
      * 0 = Read from cache (generate the files the first time)
      * 1 = Read from net without override the cache files
      * 2 = Read from net and override the cache files
      */
-    const CACHE = 0;
+    const CACHE = -1;
 
     /**
      * 0 = Do not override the fixtures