Updates failing test (just getting travis to run)

Author: tylergaw

test/fixtures/color.css

@@ -12,7 +12,7 @@ body {
 }
 
 .withAlpha {
-  color: color(black a(90%) contrast(99%));
+  color: color(black a(80%) contrast(99%));
   background-color: color(red a(50%) shade(50%));
   border-color: color(red a(80%) tint(50%));
 }

test/fixtures/color.expected.css

@@ -12,7 +12,7 @@ body {
 }
 
 .withAlpha {
-  color: rgba(255, 255, 255, 0.9);
+  color: rgba(255, 255, 255, 0.8);
   background-color: rgba(128, 0, 0, 0.5);
   border-color: rgba(255, 128, 128, 0.8);
 }