Accessibility fixes:

	- changed buttons to spans since not being used in forms
	- added aria roles to html elements
	- changed low contrast colors

Change-Id: I56e784b226baa7f9b24346446a0a023fcea633d4
Signed-off-by: Michael Davis <michael.s.davis@ibm.com>
diff --git a/app/common/directives/app-header.html b/app/common/directives/app-header.html
index a21d06a..03d7049 100644
--- a/app/common/directives/app-header.html
+++ b/app/common/directives/app-header.html
@@ -1,10 +1,10 @@
-<div id="header__wrapper">
+<div id="header__wrapper" role="banner">
 <!-- HEADER -->
 <header id="header">
     <span class="app__version float-left">OpenBMC for IBM Power Systems {{dataService.app_version}}</span>
     <a href="" class="header__logout" ng-click="logout()">Log out</a>
 </header>
-<div class="header__functions-wrapper" role="heading">
+<div class="header__functions-wrapper" aria-label="header">
     <div class="logo__wrapper"><img src="assets/images/logo.svg" class="header__logo"  alt="company logo"/></div>
 	<div class="header__server-name">
 		<p class="header__hostname">[[hostname needed]]</p>