Add test cases for summary endpoint
Add test cases for summary endpoint

* Show that '.' do not impact summary length
* Show that bolding is retained

Change-Id: Id550eba05ff9d2746834b7802bf5f987aa216e09

wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps