CentOS 7 install fails at multiple parts

[egriffith]

If you spin up an AWS EC2 Instance running the CentOS 7 AMI and choose to have Cloud9 install into that instance, the install will fail at various parts.

Issue 1: "Can't install gcc,g++"
solution: sudo yum install gcc gcc-g++

Issue 2: Can't compile tmux. "curses not found"
Solution: sudo yum install glibc-static ncurses-devel

Issue 3 "Group 'docker' not found"
Solution: sudo grouped docker && sudo usermod -aG docker $USER