A simple script that will clone all public *and* private repos the user owns (no forks!) and zip up the results.

cloner.sh

#!/bin/bash

# Author: Chris Pritchard (github.com/ChrisPritchard)
# requires jq, 7z and git be installed
# run as ./cloner.sh [personal access token] [UserName]

REPOS=$(curl -s -H "Authorization: token $1" "https://api.github.com/user/repos?&affiliation=owner&per_page=200" | jq -r '.[] | select(.fork==false) | .full_name')

rm -rf ./temp-cloner
mkdir temp-cloner

for REPO in $REPOS; do
    git clone -q "https://github.com/$REPO" temp-cloner/$REPO
done

7z a github.zip "./temp-cloner/$2/*"
rm -rf ./temp-cloner