Add loading bar to SSL certificates page

- Return new Date() instead of null when calculating expiring
  time. Expired certificates banner is sometimes visible if
  the certificates are returned before the bmc time

Signed-off-by: Yoshie Muranaka <yoshiemuranaka@gmail.com>
Change-Id: I3a2b8ac8a639f464856472013be14878151e7289
diff --git a/src/store/modules/AccessControl/SslCertificatesStore.js b/src/store/modules/AccessControl/SslCertificatesStore.js
index ef4afdb..71304b5 100644
--- a/src/store/modules/AccessControl/SslCertificatesStore.js
+++ b/src/store/modules/AccessControl/SslCertificatesStore.js
@@ -48,8 +48,8 @@
     }
   },
   actions: {
-    getCertificates({ commit }) {
-      api
+    async getCertificates({ commit }) {
+      return await api
         .get('/redfish/v1/CertificateService/CertificateLocations')
         .then(({ data: { Links: { Certificates } } }) =>
           Certificates.map(certificate => certificate['@odata.id'])