fix(challenges): improved tests for adding background/background-image

Signed-off-by: Jonathan Grah <[email protected]>

Author: jonathan-grah

challenges/01-responsive-web-design/applied-visual-design.json

@@ -2314,7 +2314,7 @@
           "text":
             "Your <code>body</code> element should have a <code>background</code> property set to a <code>url()</code> with the given link.",
           "testString":
-            "assert(code.match(/background:\\s*?url\\(\\s*(\"|'|)https:\\/\\/i\\.imgur\\.com\\/MJAkxbh\\.png\\1\\s*\\)/gi), 'Your <code>body</code> element should have a <code>background</code> property set to a <code>url()</code> with the given link.');"
+            "assert(code.match(/(background:|background-image:)\\s*?url\\(\\s*(\"|'|)https:\\/\\/i\\.imgur\\.com\\/MJAkxbh\\.png\\1\\s*\\)/gi), 'Your <code>body</code> element should have a <code>background</code> property set to a <code>url()</code> with the given link.');"
         }
       ],
       "solutions": [