Create certificate management page

Displays certificates and the ability to add up to one
of each type of certificate (as limited by the backend
implementation). HTTPS certificate and LDAP client cert
are implemented in this commit, with the ability to add
more types as needed by adding them to the constants.js
CERTIFICATE_TYPES array.

Also provides the ability to replace a certificate once
it is added.

Resolves openbmc/phosphor-webui#43

Tested: loaded onto a witherspoon and able to view and
        replace both the HTTPS certificate and the
        LDAP certificate. GUI only allows to upload an
        LDAP certificate if one doesn't already exist.
        The GUI limits the user to one file per type as
        expected at this time and provides the
        appropriate validation messages. Alert messages
        appear above the table if the certificate is
        expired or within 30 days of expiring.

Change-Id: I345267280ecd3cb257e9304886cde9ebb69b1240
Signed-off-by: beccabroek <beccabroek@gmail.com>
Signed-off-by: Yoshie Muranaka <yoshiemuranaka@gmail.com>
diff --git a/app/index.js b/app/index.js
index e4061ed..5997457 100644
--- a/app/index.js
+++ b/app/index.js
@@ -43,6 +43,7 @@
 import app_navigation from './common/directives/app-navigation.js';
 import confirm from './common/directives/confirm.js';
 import log_event from './common/directives/log-event.js';
+import certificate from './common/directives/certificate.js';
 import log_filter from './common/directives/log-filter.js';
 import log_search_control from './common/directives/log-search-control.js';
 import toggle_flag from './common/directives/toggle-flag.js';
@@ -83,6 +84,7 @@
 import redfish_controller from './redfish/controllers/redfish-controller.js';
 import configuration_index from './configuration/index.js';
 import date_time_controller from './configuration/controllers/date-time-controller.js';
+import certificate_controller from './configuration/controllers/certificate-controller.js';
 import network_controller from './configuration/controllers/network-controller.js';
 import snmp_controller from './configuration/controllers/snmp-controller.js';
 import firmware_controller from './configuration/controllers/firmware-controller.js';