fix(spinner): fixed binding the the radio buttons model (#99)

* fix(spinner): fixed binding the the radio buttons model

* fix(bar): fixed binding the the radio buttons model

Author: EladBezalel

src/app/examples/progress-spinner-configurable/progress-spinner-configurable-example.html

@@ -41,7 +41,7 @@ <h2 class="example-h2">Result</h2>
 
     <md-progress-circle
         class="example-margin"
-        [attr.color]="color"
+        [color]="color"
         [mode]="mode"
         [value]="value">
     </md-progress-circle>