Prevent 500 on MR page if merge_event missing

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Decline push if repository does not exist

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Bolder event title and lighter color for event body

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Execute project services asynchronously

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

Async services

Fixes #1814

See merge request !1312
Merge branch 'small-fixes' into 'master'

Small fixes

Improve application stability over unexpected cases

See merge request !1310
Merge branch 'improve-activity-ui' into 'master'

Improve activity UI

See merge request !1311