Job Failed #92

Job #92 failed for f0d16e26:

• Due to Matterhook library changing signature for attachments: https://gitlab.openci.io/openci/matterbridge/commit/4f2ae7b73f967e1d5448094f07f472405341ab71?view=inline
• Example of how to fix: https://github.com/nlopes/slack/blob/master/examples/messages/messages.go (pretty close to what's there now)