created new styling for CNVS-15493

new colors are based on $canvas-neutral

contrast for context on quizzes tab. can be viewed at '/quizzes'

rewrote quiz list text and icons to have single darken function. also, one less selector!

regular: #808080 on #fff :: 3.95:1
high contrast: #6d6d6d on #fff :: 5.17:1

Test plan:
- Navigated to quizzes tab. If there are no quizzes create one. 
- Verify contrast of publish icon, and 'pts' and 'question' text has been updated. You can verify the color contrast using http://webaim.org/resources/contrastchecker/
- After verifying enable high contrast.
- Repeat previous tests to verify high contrast color ratios.
 
Change-Id: I83ec5baf03d0264efcf0d7110c7f2be240f15b83
Reviewed-on: https://gerrit.instructure.com/41679
Reviewed-by: Chris Hart <chart@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Anna Koalenz <akoalenz@instructure.com>
Product-Review: Matt Fairbourn <mfairbourn@instructure.com>

Author: Vincent Gonzalez

app/stylesheets/components/_item-groups.scss

@@ -233,7 +233,6 @@ is for items that are not draggable.
   }
 
   .ellipses {
-    color: #7c7c7c;
     overflow: hidden;
     white-space: nowrap;
     text-overflow: ellipsis;
@@ -301,6 +300,7 @@ is for items that are not draggable.
 
   .publish-icon {
     margin-right: 22px;
+    
 
     i[class*=icon-]:before,
     i[class^=icon-]:before {
@@ -329,4 +329,4 @@ is for items that are not draggable.
 .ig-text {
   color: #3d454c;
   font-size: 15px;
-}
+}

app/stylesheets/pages/quizzes/_quizzes.sass

@@ -30,8 +30,11 @@ $selectedBorderColor: #31b5ff
 li.quiz
   cursor: pointer
 
-  .ellipses
-    color: #7c7c7c
+  .ellipses, i[class^=icon-]:not(.icon-publish)
+    @if $use_high_contrast 
+      color: $canvas-neutral
+    @else 
+      color: darken($canvas-neutral, 40)
 
   .ig-title
     right: 554px