Move gravatar url compose to separate service

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Dont expose user email via API

To prevent leaking of users info we reduce amount of user information
retrieved via API for normal users.

What user can get via API:

* if not admin: only id, state, name, username and avatar_url
* if admin: all user information
* about himself: all informaion

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Fix gravatar size and update docs for new users API

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Add a test for issue sentence generation
Fix helper specs

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Fix api specs

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Add /api/users test for admin role. Updated CHANGELOG

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge branch 'more-secure-api' into 'master'

More secure api

Dont expose user email via API. Fixes #1314
Merge branch 'ce_issues_sentence' into 'master'

Issues sentence helper

This will make merging CE into EE later easier.