Store coverage information in cache

package.json

@@ -108,7 +108,7 @@
         "c9.ide.save": "#e00549cb0f",
         "c9.ide.scm": "#2398826541",
         "c9.ide.terminal.monitor": "#b76f1c9f24",
-        "c9.ide.test": "#0359e40079",
+        "c9.ide.test": "#d48181f8f6",
         "c9.ide.test.mocha": "#88fee23065",
         "c9.ide.theme.flat": "#2de8414db7",
         "c9.ide.threewaymerge": "#229382aa0b",