Update setup-Linux-amzn-2.sh

[dchassin]

This PR fixes the EC2 setup script.

Current issues

None

Code changes

• Add xz-devel to the setup script.

Documentation changes

None

Test and Validation Notes

None

[catzzz]

This PR fixes the EC2 setup script and sets the environment variable in EC2 #1066.

Current issues

There might be a better way to set the environment variable in EC2 in the first time installation.
A global variable was set in setup-Linux-amzn-2.sh.

echo "export PATH=/usr/local/bin:$PATH" >> /etc/profile.d/setVars.sh && \
source /etc/profile.d/setVars.sh

However, the PATH will be written into memory after reboot. So I have to change the installation process to avoid rebooting the server.

Documentation changes

AWS EC2 Installation

1. Set the path variable

host% sudo su
host% export PATH=/usr/local/bin:$PATH

2. Change work dictionary and clone GitHub repository

host% cd /usr/local/src
host% git clone https://github.com/slacgismo/gridlabd gridlabd

3. Run installation

host% gridlabd/install.sh

[dchassin]

Tested out ok c3.2xlarge.