Set a minimum coverage threshold for javascript

This patch sets a minimum test coverage for the javascript code
in octavia-dashboard. We are currently at 100% coverage, so this
patch sets 100% as the minimum.

Change-Id: Ieeeec6273cd371a30b56370972711af45fadec30

octavia_dashboard/karma.conf.js

@@ -141,7 +141,15 @@ module.exports = function (config) {
     coverageReporter: {
       type: 'html',
       dir: '../cover/',
-      subdir: '.'
+      subdir: '.',
+      check: {
+        global: {
+          statements: 100,
+          branches: 100,
+          functions: 100,
+          lines: 100
+        }
+      }
     },
 
     // Coverage threshold values.