fix highlight test for failed highlighting

not sure how this ever succeeded, but it's failing now

IPython/html/tests/base/highlight.js

@@ -1,58 +1,58 b''
 casper.notebook_test(function () {
     this.on('remote.callback', function(data){
         if(data.error_expected){
             that.test.assertEquals(
                 data.error,
-                data.expected,
-                "!highlight: " + data.provided + " errors " + data.expected
+                true,
+                "!highlight: " + data.provided + " errors"
             );
         }else{
             that.test.assertEquals(
                 data.observed,
                 data.expected,
                 "highlight: " + data.provided + " as " + data.expected
             );
         }
     });
     
     var that = this;
     // syntax highlighting
     [
         {to: "gfm"},
         {to: "python"},
         {to: "ipython"},
         {to: "ipythongfm"},
         {to: "text/x-markdown", from: [".md"]},
         {to: "text/x-python", from: [".py", "Python"]},
         {to: "application/json", from: ["json", "JSON"]},
         {to: "text/x-ruby", from: [".rb", "ruby", "Ruby"]},
         {to: "application/ld+json", from: ["json-ld", "JSON-LD"]},
         {from: [".pyc"], error: true},
         {from: ["../"], error: true},
         {from: ["//"], error: true},
     ].map(function (mode) {
         (mode.from || []).concat(mode.to || []).map(function(from){
             casper.evaluate(function(from, expected, error_expected){
                 IPython.utils.requireCodeMirrorMode(from, function(observed){
                     window.callPhantom({
                         provided: from,
                         expected: expected,
                         observed: observed,
                         error_expected: error_expected
                     });
                 }, function(error){
                     window.callPhantom({
                         provided: from,
                         expected: expected,
-                        error: error,
+                        error: true,
                         error_expected: error_expected
                     }); 
                 });
             }, {
                 from: from,
                 expected: mode.to,
                 error_expected: mode.error
             });
         });
     });
 });
  No newline at end of file