Solution:

1. Recon
2. Cloning git wget -r http://54.85.105.103/.git/
3. Extracting commits https://github.com/internetwache/GitTools/
4. Inviting ourselves to Slack using API
5. Enum
6. Checking the key chmod 600 id_rsa && ssh -i id_rsa mikeatcorp@54.85.105.103
7. Looking for flag