power-operations: misc changes

    * Accessibility tweaks.
    * Minor style updates.
    * Navigation updates.

Change-Id: I7ceea9697ccd5853268f9bd8704e73b367e1bc0b
Signed-off-by: Michael Davis <michael.s.davis@ibm.com>
diff --git a/src/header.html b/src/header.html
index 7c14f2f..13584cf 100644
--- a/src/header.html
+++ b/src/header.html
@@ -10,8 +10,8 @@
     <div class="logo__wrapper"></div>
     <div class="header__functions">
         <a href="">Server health<span class="status-light__error">Error</span></a>
-        <a href="power-operations.html" class="header__server-power">Server power<span class="status-light__good">On</span></a>
+        <a href="power-operations.html" class="header__server-power" role="button">Server power<span class="status-light__good">On</span></a>
         <p class="header__refresh">Page last refreshed <span>3:20:12 Feb 12 2017</span></p>
-        <button class="header__page-refresh"><img src="img/icon-refresh-white.svg" /></button>
+        <button class="header__page-refresh"><img src="img/icon-refresh-white.svg" alt="refresh page" role="button"/></button>
     </div>
 </div>
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