added 'none' as valid display option

tasks/jasmine.js

@@ -28,6 +28,11 @@ module.exports = function(grunt) {
   var summary = [];
 
   var symbols = {
+    none : {
+      check : '',
+      error : '',
+      splat : ''
+    },
     short : {
       check : '.',
       error : 'X',
@@ -44,6 +49,11 @@ module.exports = function(grunt) {
   //https://github.com/visionmedia/mocha/pull/641
   if (process && process.platform === 'win32') {
     symbols = {
+      none : {
+        check : '',
+        error : '',
+        splat : ''
+      },
       short : {
         check : '.',
         error : '\u00D7',
@@ -296,9 +306,12 @@ module.exports = function(grunt) {
         // If we haven't written out since we've started
         if (thisRun.cleanConsole) {
           // then append to the current line.
+          if (options.display !== 'none') {
             grunt.log.writeln('...' + symbols[options.display][symbol]);
+          }
         } else {
           // Otherwise reprint the current spec and status.
+          if (options.display !== 'none') {
             grunt.log.writeln(
               indent(indentLevel) + '...' +
               chalk.grey(specMetaData.description) + '...' +
@@ -306,6 +319,7 @@ module.exports = function(grunt) {
             );
           }
         }
+      }
 
       specMetaData.failedExpectations.forEach(function(error, i){
         var specIndex = ' ('+(i+1)+')';