Clean up headers

Updates headers to match style guide and makes them consistent
throughout pages in the GUI. Removes instances where a header
element existed and a different header style was being applied.
For example, <h2 class="h4">

Tested: Ran GUI locally and verified that headers look consistent
and have the appropriate sizing while using Chrome, Firefox and
Safari.

Change-Id: I187136298ed2bfd36c40c2b80d5a4f20947cbe56
Signed-off-by: beccabroek <beccabroek@gmail.com>
diff --git a/app/server-control/controllers/bmc-reboot-controller.html b/app/server-control/controllers/bmc-reboot-controller.html
index dece701..627e60c 100644
--- a/app/server-control/controllers/bmc-reboot-controller.html
+++ b/app/server-control/controllers/bmc-reboot-controller.html
@@ -4,7 +4,7 @@
   </div>
   <div class="row column">
     <div class="page-header">
-      <p class="inline h4">Current BMC boot status</p>
+      <h2 class="inline">Current BMC boot status</h2>
       <div class="float-right bmc-reboot__status-log inline">BMC last reboot at
         <span class="courier-bold">{{reboot_time | localeDate}}</span></div>
     </div>